HAMDAN v. RUMSFELD, SECRETARY OF DEFENSE, et al.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
557 OCTOBER TERM, 2005
Syllabus
HAMDAN v. RUMSFELD, SECRETARY OF DEFENSE,
et al.
certiorari to the united states court of appeals for
the district of columbia circuit
No. 05–184. Argued March 28, 2006—Decided June 29, 2006
Pursuant to Congress’ Joint Resolution authorizing the President to “use
all necessary and appropriate force against those nations, organizations,
or persons he determines planned, authorized, committed, or aided” the
September 11, 2001, al Qaeda terrorist attacks (AUMF), U. S. Armed
Forces invaded Afghanistan. During the hostilities, in 2001, militia
forces captured petitioner Hamdan, a Yemeni national, and turned him
over to the U. S. military, which, in 2002, transported him to prison in
Guantanamo Bay, Cuba. Over a year later, the President deemed Ham
dan eligible for trial by military commission for then-unspecified crimes.
After another year, he was charged with conspiracy “to commit . . .
offenses triable by military commission.” In habeas and mandamus pe
titions, Hamdan asserted that the military commission lacks authority
to try him because (1) neither congressional Act nor the common law of
war supports trial by this commission for conspiracy, an offense that,
Hamdan says, is not a violation of the law of war; and (2) the procedures
adopted to try him violate basic tenets of military and international law,
including the principle that a defendant must be permitted to see and
hear the evidence against him.
The District Court granted habeas relief and stayed the commission’s
proceedings, concluding that the President’s authority to establish mili
tary commissions extends only to offenders or offenses triable by such
a commission under the law of war; that such law includes the Third
Geneva Convention; that Hamdan is entitled to that Convention’s full
protections until adjudged, under it, not to be a prisoner of war; and
that, whether or not Hamdan is properly classified a prisoner of war,
the commission convened to try him was established in violation of both
the Uniform Code of Military Justice (UCMJ), 10 U. S. C. § 801 et seq.,
and Common Article 3 of the Third Geneva Convention because it had
the power to convict based on evidence the accused would never see or
hear. The D. C. Circuit reversed. Although it declined the Govern
ment’s invitation to abstain from considering Hamdan’s challenge,
cf. Schlesinger v. Councilman, 420 U. S. 738, the appeals court ruled, on
the merits, that Hamdan was not entitled to relief because the Geneva
Conventions are not judicially enforceable. The court also concluded

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
558 HAMDAN v. RUMSFELD
Syllabus
that Ex parte Quirin, 317 U. S. 1, foreclosed any separation-of-powers
objection to the military commission’s jurisdiction, and that Hamdan’s
trial before the commission would violate neither the UCMJ nor Armed
Forces regulations implementing the Geneva Conventions.
Held: The judgment is reversed, and the case is remanded.
415 F. 3d 33, reversed and remanded.
Justice Stevens delivered the opinion of the Court, except as to
Parts V and VI–D–iv, concluding:
1. The Government’s motion to dismiss, based on the Detainee Treat
ment Act of 2005 (DTA), is denied. DTA § 1005(e)(1) provides that “no
court . . . shall have jurisdiction to hear or consider . . . an application
for . . . habeas corpus filed by . . . an alien detained . . . at Guantanamo
Bay.” Section 1005(h)(2) provides that §§ 1005(e)(2) and (3)—which
give the D. C. Circuit “exclusive” jurisdiction to review the final deci
sions of, respectively, combatant status review tribunals and military
commissions—“shall apply with respect to any claim whose review is . . .
pending on” the DTA’s effective date, as was Hamdan’s case. The Gov
ernment’s argument that §§ 1005(e)(1) and (h) repeal this Court’s juris
diction to review the decision below is rebutted by ordinary principles
of statutory construction. A negative inference may be drawn from
Congress’ failure to include § 1005(e)(1) within the scope of § 1005(h)(2).
Cf., e. g., Lindh v. Murphy, 521 U. S. 320, 330. “If . . . Congress was
reasonably concerned to ensure that [§§ 1005(e)(2) and (3)] be applied to
pending cases, it should have been just as concerned about [§ 1005(e)(1)],
unless it had the different intent that the latter [section] not be applied
to the general run of pending cases.” Id., at 329. If anything, the
evidence of deliberate omission is stronger here than it was in Lindh.
The legislative history shows that Congress not only considered the re
spective temporal reaches of §§ 1005(e)(1), (2), and (3) together at every
stage, but omitted paragraph (1) from its directive only after having
rejected earlier proposed versions of the statute that would have in
cluded what is now paragraph (1) within that directive’s scope. Con
gress’ rejection of the very language that would have achieved the re
sult the Government urges weighs heavily against the Government’s
interpretation. See Doe v. Chao, 540 U. S. 614, 621–623. Pp. 572–584.
2. The Government argues unpersuasively that abstention is appro
priate under Councilman, which concluded that, as a matter of comity,
federal courts should normally abstain from intervening in pending
courts-martial against service members, see 420 U. S., at 740. Neither
of the comity considerations Councilman identified weighs in favor of
abstention here. First, the assertion that military discipline and, there

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
559 Cite as: 548 U. S. 557 (2006)
Syllabus
fore, the Armed Forces’ efficient operation, are best served if the mili
tary justice system acts without regular interference from civilian
courts, see id., at 752, is inapt because Hamdan is not a service member.
Second, the view that federal courts should respect the balance Con
gress struck when it created “an integrated system of military courts
and review procedures” is inapposite, since the tribunal convened to try
Hamdan is not part of that integrated system. Rather than Council
man, the most relevant precedent is Ex parte Quirin, where the Court,
far from abstaining pending the conclusion of ongoing military proceed
ings, expedited its review because of (1) the public importance of the
questions raised, (2) the Court’s duty, in both peace and war, to preserve
the constitutional safeguards of civil liberty, and (3) the public interest
in a decision on those questions without delay, 317 U. S., at 19. The
Government has identified no countervailing interest that would permit
federal courts to depart from their general duty to exercise the jurisdic
tion Congress has conferred on them. Pp. 584–590.
3. The military commission at issue is not expressly authorized by
any congressional Act. Quirin held that Congress had, through Article
of War 15, sanctioned the use of military commissions to try offenders
or offenses against the law of war. 317 U. S., at 28. UCMJ Art. 21,
which is substantially identical to the old Art. 15, reads: “The jurisdic
tion [of] courts-martial shall not be construed as depriving military
commissions . . . of concurrent jurisdiction in respect of offenders or
offenses that by statute or by the law of war may be tried by such . . .
commissions.” 10 U. S. C. § 821. Contrary to the Government’s asser
tion, even Quirin did not view that authorization as a sweeping mandate
for the President to invoke military commissions whenever he deems
them necessary. Rather, Quirin recognized that Congress had simply
preserved what power, under the Constitution and the common law of
war, the President already had to convene military commissions—with
the express condition that he and those under his command comply with
the law of war. See 317 U. S., at 28–29. Neither the AUMF nor the
DTA can be read to provide specific, overriding authorization for the
commission convened to try Hamdan. Assuming the AUMF activated
the President’s war powers, see Hamdi v. Rumsfeld, 542 U. S. 507, and
that those powers include authority to convene military commissions in
appropriate circumstances, see, e. g., id., at 518, there is nothing in the
AUMF’s text or legislative history even hinting that Congress intended
to expand or alter the authorization set forth in UCMJ Art. 21.
Cf. Ex parte Yerger, 8 Wall. 85, 105. Likewise, the DTA cannot be read
to authorize this commission. Although the DTA, unlike either Art.
21 or the AUMF, was enacted after the President convened Hamdan’s

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
560 HAMDAN v. RUMSFELD
Syllabus
commission, it contains no language authorizing that tribunal or any
other at Guantanamo Bay. Together, the UCMJ, the AUMF, and the
DTA at most acknowledge a general Presidential authority to convene
military commissions in circumstances where justified under the Con
stitution and laws, including the law of war. Absent a more specific
congressional authorization, this Court’s task is, as it was in Quirin,
to decide whether Hamdan’s military commission is so justified.
Pp. 590–595.
4. The military commission at issue lacks the power to proceed be
cause its structure and procedures violate both the UCMJ and the four
Geneva Conventions signed in 1949. Pp. 613–635.
(a) The commission’s procedures, set forth in Commission Order
No. 1, provide, among other things, that an accused and his civilian coun
sel may be excluded from, and precluded from ever learning what evi
dence was presented during, any part of the proceeding the official who
appointed the commission or the presiding officer decides to “close.”
Grounds for closure include the protection of classified information, the
physical safety of participants and witnesses, the protection of intelli
gence and law enforcement sources, methods, or activities, and “other
national security interests.” Appointed military defense counsel must
be privy to these closed sessions, but may, at the presiding officer’s
discretion, be forbidden to reveal to the client what took place therein.
Another striking feature is that the rules governing Hamdan’s commis
sion permit the admission of any evidence that, in the presiding officer’s
opinion, would have probative value to a reasonable person. Moreover,
the accused and his civilian counsel may be denied access to classified
and other “protected information,” so long as the presiding officer con
cludes that the evidence is “probative” and that its admission without
the accused’s knowledge would not result in the denial of a full and fair
trial. Pp. 613–615.
(b) The Government objects to this Court’s consideration of a pro
cedural challenge at this stage on the grounds, inter alia, that Hamdan
will be able to raise such a challenge following a final decision under the
DTA, and that there is no basis to presume, before the trial has even
commenced, that it will not be conducted in good faith and according to
law. These contentions are unsound. First, because Hamdan appar
ently is not subject to the death penalty (at least as matters now stand)
and may receive a prison sentence shorter than 10 years, he has no
automatic right to federal-court review of the commission’s “final deci
sion” under DTA § 1005(e)(3). Second, there is a basis to presume that
the procedures employed during Hamdan’s trial will violate the law: He
will be, and indeed already has been, excluded from his own trial.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
561 Cite as: 548 U. S. 557 (2006)
Syllabus
Thus, review of the procedures in advance of a “final decision” is appro
priate. Pp. 615–616.
(c) Because UCMJ Article 36 has not been complied with here, the
rules specified for Hamdan’s commission trial are illegal. The proce
dures governing such trials historically have been the same as those
governing courts-martial. Although this uniformity principle is not in
flexible and does not preclude all departures from court-martial proce
dures, any such departure must be tailored to the exigency that necessi
tates it. That understanding is reflected in Art. 36(b), which provides
that the procedural rules the President promulgates for courts-martial
and military commissions alike must be “uniform insofar as practicable,”
10 U. S. C. § 836(b). The “practicability” determination the President
has made is insufficient to justify variances from the procedures govern
ing courts-martial. The President here has determined, pursuant to
the requirement of Art. 36(a), that it is impracticable to apply the rules
and principles of law that govern “the trial of criminal cases in the
United States district courts” to Hamdan’s commission. The President
has not, however, made a similar official determination that it is imprac
ticable to apply the rules for courts-martial. And even if subsection
(b)’s requirements could be satisfied without an official practicability de
termination, that subsection’s requirements are not satisfied here.
Nothing in the record demonstrates that it would be impracticable to
apply court-martial rules here. There is no suggestion, e. g., of any lo
gistical difficulty in securing properly sworn and authenticated evidence
or in applying the usual principles of relevance and admissibility. It is
not evident why the danger posed by international terrorism, consider
able though it is, should require, in the case of Hamdan’s trial, any vari
ance from the court-martial rules. The absence of any showing of
impracticability is particularly disturbing when considered in light of
the clear and admitted failure to apply one of the most fundamental
protections afforded not just by the Manual for Courts-Martial but
also by the UCMJ itself: The right to be present. See 10 U. S. C.
§ 839(c). Because the jettisoning of so basic a right cannot lightly
be excused as “practicable,” the court-martial rules must apply. Since
it is undisputed that Commission Order No. 1 deviates in many sig
nificant respects from those rules, it necessarily violates Art. 36(b).
Pp. 617–625.
(d) The procedures adopted to try Hamdan also violate the Geneva
Conventions. The D. C. Circuit dismissed Hamdan’s challenge in this
regard on the grounds, inter alia, that the Conventions are not judicially
enforceable and that, in any event, Hamdan is not entitled to their pro
tections. Neither of these grounds is persuasive. Pp. 625–631.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
562 HAMDAN v. RUMSFELD
Syllabus
(i) The appeals court relied on a statement in Johnson v. Eisen
trager, 339 U. S. 763, 789, n. 14, suggesting that this Court lacked power
even to consider the merits of a Convention argument because the politi
cal and military authorities had sole responsibility for observing and
enforcing prisoners’ rights under the Convention. However, Eisen
trager does not control here because, regardless of the nature of the
rights conferred on Hamdan, cf. United States v. Rauscher, 119 U. S.
407, they are indisputably part of the law of war, see Hamdi, 542 U. S.,
at 520–521, compliance with which is the condition upon which UCMJ
Art. 21 authority is granted. Pp. 626–628.
(ii) Alternatively, the appeals court agreed with the Government
that the Conventions do not apply because Hamdan was captured during
the war with al Qaeda, which is not a Convention signatory, and that
conflict is distinct from the war with signatory Afghanistan. The Court
need not decide the merits of this argument because there is at least
one provision of the Geneva Conventions that applies here even if the
relevant conflict is not between signatories. Common Article 3, which
appears in all four Conventions, provides that, in a “conflict not of an
international character occurring in the territory of one of the High
Contracting Parties [i. e., signatories], each Party to the conflict shall
be bound to apply, as a minimum,” certain provisions protecting
“[p]ersons . . . placed hors de combat by . . . detention,” including
a prohibition on “the passing of sentences . . . without previous judg
ment . . . by a regularly constituted court affording all the judicial guar
antees . . . recognized as indispensable by civilized peoples.” The D. C.
Circuit ruled Common Article 3 inapplicable to Hamdan because the
conflict with al Qaeda is international in scope and thus not a “conflict
not of an international character.” That reasoning is erroneous. That
the quoted phrase bears its literal meaning and is used here in contradis
tinction to a conflict between nations is demonstrated by Common Arti
cle 2, which limits its own application to any armed conflict between
signatories and provides that signatories must abide by all terms of the
Conventions even if another party to the conflict is a nonsignatory, so
long as the nonsignatory “accepts and applies” those terms. Common
Article 3, by contrast, affords some minimal protection, falling short
of full protection under the Conventions, to individuals associated with
neither a signatory nor even a nonsignatory who are involved in a
conflict “in the territory of ” a signatory. The latter kind of conflict
does not involve a clash between nations (whether signatories or not).
Pp. 628–631.
(iii) While Common Article 3 does not define its “regularly con
stituted court” phrase, other sources define the words to mean an “ordi
nary military cour[t]” that is “established and organized in accordance

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
563 Cite as: 548 U. S. 557 (2006)
Syllabus
with the laws and procedures already in force in a country.” The regu
lar military courts in our system are the courts-martial established by
congressional statute. At a minimum, a military commission can be
“regularly constituted” only if some practical need explains deviations
from court-martial practice. No such need has been demonstrated
here. Pp. 631–633.
(iv) Common Article 3’s requirements are general, crafted to ac
commodate a wide variety of legal systems, but they are requirements
nonetheless. The commission convened to try Hamdan does not meet
those requirements. P. 635.
(e) Even assuming that Hamden is a dangerous individual who
would cause great harm or death to innocent civilians given the opportu
nity, the Executive nevertheless must comply with the prevailing rule
of law in undertaking to try him and subject him to criminal punish
ment. P. 635.
Justice Stevens, joined by Justice Souter, Justice Ginsburg,
and Justice Breyer, concluded in Parts V and VI–D–iv:
1. The Government has not charged Hamdan with an “offens[e] . . .
that . . . by the law of war may be tried by military commissio[n],” 10
U. S. C. § 821. Of the three sorts of military commissions used histori
cally, the law-of-war type used in Quirin and other cases is the only
model available to try Hamdan. Among the preconditions, incorpo
rated in Article of War 15 and, later, UCMJ Art. 21, for such a tribunal’s
exercise of jurisdiction are, inter alia, that it must be limited to trying
offenses committed within the convening commander’s field of command,
i. e., within the theater of war, and that the offense charged must have
been committed during, not before or after, the war. Here, Hamdan is
not alleged to have committed any overt act in a theater of war or
on any specified date after September 11, 2001. More importantly, the
offense alleged is not triable by law-of-war military commission. Al
though the common law of war may render triable by military commis
sion certain offenses not defined by statute, Quirin, 317 U. S., at 30, the
precedent for doing so with respect to a particular offense must be plain
and unambiguous, cf., e. g., Loving v. United States, 517 U. S. 748, 771.
That burden is far from satisfied here. The crime of “conspiracy” has
rarely if ever been tried as such in this country by any law-of-war mili
tary commission not exercising some other form of jurisdiction, and does
not appear in either the Geneva Conventions or the Hague Conven
tions—the major treaties on the law of war. Moreover, that conspiracy
is not a recognized violation of the law of war is confirmed by other
international sources, including, e. g., the International Military Tribu
nal at Nuremberg, which pointedly refused to recognize conspiracy to
commit war crimes as such a violation. Because the conspiracy charge

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
564 HAMDAN v. RUMSFELD
Syllabus
does not support the commission’s jurisdiction, the commission lacks au
thority to try Hamdan. Pp. 595–613.
2. The phrase “all the judicial guarantees . . . recognized as indispen
sable by civilized peoples” in Common Article 3 of the Geneva Conven
tions is not defined, but it must be understood to incorporate at least
the barest of the trial protections recognized by customary international
law. The procedures adopted to try Hamdan deviate from those gov
erning courts-martial in ways not justified by practical need, and thus
fail to afford the requisite guarantees. Moreover, various provisions of
Commission Order No. 1 dispense with the principles, which are indis
putably part of customary international law, that an accused must, ab
sent disruptive conduct or consent, be present for his trial and must be
privy to the evidence against him. Pp. 633–635.
Justice Kennedy, agreeing that Hamdan’s military commission is
unauthorized under the Uniform Code of Military Justice, 10 U. S. C.
§§ 836 and 821, and the Geneva Conventions, concluded that there is
therefore no need to decide whether Common Article 3 of the Conven
tions requires that the accused have the right to be present at all stages
of a criminal trial or to address the validity of the conspiracy charge
against Hamdan. Pp. 653–655.
Stevens, J., announced the judgment of the Court and delivered the
opinion of the Court with respect to Parts I through IV, VI through
VI–D–iii, VI–D–v, and VII, in which Kennedy, Souter, Ginsburg, and
Breyer, JJ., joined, and an opinion with respect to Parts V and VI–D–iv,
in which Souter, Ginsburg, and Breyer, JJ., joined. Breyer, J., filed
a concurring opinion, in which Kennedy, Souter, and Ginsburg, JJ.,
joined, post, p. 636. Kennedy, J., filed an opinion concurring in part, in
which Souter, Ginsburg, and Breyer, JJ., joined as to Parts I and II,
post, p. 636. Scalia, J., filed a dissenting opinion, in which Thomas and
Alito, JJ., joined, post, p. 655. Thomas, J., filed a dissenting opinion, in
which Scalia, J., joined, and in which Alito, J., joined as to all but Parts I,
II–C–1, and III–B–2, post, p. 678. Alito, J., filed a dissenting opinion, in
which Scalia and Thomas, JJ., joined as to Parts I through III, post,
p. 725. Roberts, C. J., took no part in the consideration or decision of
the case.
Neal Katyal argued the cause for petitioner. With him
on the briefs were Harry H. Schneider, Jr., Joseph M.
McMillan, Charles C. Sipos, Charles Swift, Thomas C.
Goldstein, Amy Howe, and Kevin K. Russell.
Solicitor General Clement argued the cause for respond
ents. With him on the brief were Assistant Attorney Gen

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
565 Cite as: 548 U. S. 557 (2006)
Counsel
eral Keisler, Deputy Solicitor General Garre, Deputy As
sistant Attorney General Katsas, Jonathan L. Marcus,
Kannon K. Shanmugam, Douglas N. Letter, and Robert M.
Loeb.*
*Briefs of amici curiae urging reversal were filed for the American
Civil Liberties Union by Steven R. Shapiro, Ben Wizner, and Lee Gelernt;
for the American Jewish Committee et al. by Marvin L. Gray, Jr., Jeffrey
L. Fisher, Jeffrey P. Sinensky, Kara H. Stein, John W. Whitehead, Elliot
M. Mincberg, Arthur H. Bryant, and Victoria W. Ni; for the Association
of the Bar of the City of New York et al. by James J. Benjamin, Jr., and
Steven M. Pesner; for the Brennan Center for Justice et al. by Sidney S.
Rosdeitcher and Jonathan Hafetz; for the Cato Institute by Timothy
Lynch; for the Center for Constitutional Rights et al. by Barbara J. Ol
shansky and William H. Goodman; for International Law Professors by
Linda A. Malone and Jordan J. Paust; for Law Professors by Claudia
Callaway; for Military Law Historians, Scholars, and Practitioners by Te
resa Wynn Roseborough, Charles Lester, Jr., John A. Chandler, and Eliza
beth V. Tanis; for the National Association of Criminal Defense Lawyers
by Donald G. Rehkopf, Jr.; for the National Institute of Military Justice
et al. by Eugene R. Fidell, Stephen A. Saltzburg, Kathleen A. Duignan,
and Diane Marie Amann; for Specialists in Conspiracy and International
Law by George P. Fletcher, pro se; for the Yemeni National Organization
for Defending Rights and Freedoms by Lawrence D. Rosenberg; for Made
leine K. Albright et al. by Harold Hongju Koh and Jonathan M. Freiman;
for David Brahms et al. by Andrew J. Pincus, Jay C. Johnson, and Andrew
Tauber; for Norman Dorsen et al. by Burt Neuborne; for Louise Doswald-
Beck et al. by Bridget Arimond, David J. Scheffer, and Steven A. Kauf
man; for Richard A. Epstein et al. by Aaron M. Panner, Joseph S. Hall,
and Mr. Epstein, pro se; for Louis Fisher by Lawrence S. Lustberg; for
Ibrahim Ahmed Mahmoud al Qosi by Paul S. Reichler and Sharon A.
Shaffer; for Binyam Mohamed by Clive A. Stafford Smith and Joseph
Margulies; and for Jack N. Rakove et al. by Pamela S. Karlan.
Briefs of amici curiae urging affirmance were filed for the American
Center for Law and Justice et al. by Jay Alan Sekulow, Stuart J. Roth,
James M. Henderson, Sr., Colby M. May, and Robert W. Ash; for Common
Defence by Daniel P. Collins; for Former Attorneys General of the United
States et al. by Andrew G. McBride and Kathryn Comerford Todd; and
for the Washington Legal Foundation et al. by Daniel J. Popeo and Rich
ard A. Samp.
Briefs of amici curiae were filed for the Human Rights Committee of
the Bar of England and Wales et al. by Stephen J. Pollak and John
Townsend Rich; for the Center for National Security Studies et al. by

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
566 HAMDAN v. RUMSFELD
Opinion of the Court
Justice Stevens announced the judgment of the Court
and delivered the opinion of the Court with respect to Parts
I through IV, Parts VI through VI–D–iii, Part VI–D–v, and
Part VII, and an opinion with respect to Parts V and VI–D–
iv, in which Justice Souter, Justice Ginsburg, and Jus
tice Breyer join.
Petitioner Salim Ahmed Hamdan, a Yemeni national, is in
custody at an American prison in Guantanamo Bay, Cuba.
In November 2001, during hostilities between the United
States and the Taliban (which then governed Afghanistan),
Hamdan was captured by militia forces and turned over to
the U. S. military. In June 2002, he was transported to
Guantanamo Bay. Over a year later, the President deemed
him eligible for trial by military commission for then
unspecified crimes. After another year had passed, Hamdan
was charged with one count of conspiracy “to commit . . .
offenses triable by military commission.” App. to Pet. for
Cert. 65a.
John Payton, Seth P. Waxman, Paul R. Q. Wolfson, Kate Martin, and
Joseph Onek; for Certain Former Federal Judges by Paul C. Saunders;
for the Criminal Justice Legal Foundation by Kent S. Scheidegger; for
Human Rights First et al. by Robert P. LoBue and Deborah Pearlstein;
for Legal Scholars and Historians by Daniel C. Tepstein; for the Office of
Chief Defense Counsel, Office of Military Commissions, by Dwight H. Sul
livan and Michael D. Mori; for Retired Generals and Admirals et al. by
David H. Remes; for the Urban Morgan Institute for Human Rights by
Christopher J. Wright and Timothy J. Simeone; for Lawrence M. Fried
man et al. by William F. Alderman; for Ryan Goodman et al. by Mark A.
Packman; for Senator Lindsey Graham et al. by Jeffrey A. Lamken; for
Louis Henkin et al. by Carlos M. Va´ zquez, pro se; for David Hicks by
Joshua L. Dratel, Mr. Mori, Marc A. Goldman, and Michael B. DeSanctis;
for Arthur R. Miller by Mr. Remes; for Richard D. Rosen et al. by Steven
H. Goldblatt; for More Than 300 Detainees Incarcerated at U. S. Naval
Station, Guantanamo Bay, Cuba, et al. by Thomas B. Wilner, Neil H. Kos
lowe, and Kristine A. Huskey; and for 422 Current and Former Members
of the United Kingdom and European Union Parliaments by Claude B.
Stansbury.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
567 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
Hamdan filed petitions for writs of habeas corpus and man
damus to challenge the Executive Branch’s intended means
of prosecuting this charge. He concedes that a court
martial constituted in accordance with the Uniform Code of
Military Justice (UCMJ), 10 U. S. C. § 801 et seq. (2000 ed.
and Supp. III), would have authority to try him. His objec
tion is that the military commission the President has con
vened lacks such authority, for two principal reasons: First,
neither congressional Act nor the common law of war sup
ports trial by this commission for the crime of conspiracy—
an offense that, Hamdan says, is not a violation of the law
of war. Second, Hamdan contends, the procedures that the
President has adopted to try him violate the most basic ten
ets of military and international law, including the principle
that a defendant must be permitted to see and hear the evi
dence against him.
The District Court granted Hamdan’s request for a writ of
habeas corpus. 344 F. Supp. 2d 152 (DC 2004). The Court
of Appeals for the District of Columbia Circuit reversed.
415 F. 3d 33 (2005). Recognizing, as we did over a half cen
tury ago, that trial by military commission is an extraordi
nary measure raising important questions about the balance
of powers in our constitutional structure, Ex parte Quirin,
317 U. S. 1, 19 (1942), we granted certiorari. 546 U. S. 1002
(2005).
For the reasons that follow, we conclude that the military
commission convened to try Hamdan lacks power to proceed
because its structure and procedures violate both the UCMJ
and the Geneva Conventions. Four of us also conclude, see
Part V, infra, that the offense with which Hamdan has been
charged is not an “offens[e] that by . . . the law of war may
be tried by military commissions.” 10 U. S. C. § 821.
I
On September 11, 2001, agents of the al Qaeda terrorist
organization hijacked commercial airplanes and attacked the

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
568 HAMDAN v. RUMSFELD
Opinion of the Court
World Trade Center in New York City and the national head
quarters of the Department of Defense in Arlington, Vir
ginia. Americans will never forget the devastation wrought
by these acts. Nearly 3,000 civilians were killed.
Congress responded by adopting a Joint Resolution au
thorizing the President to “use all necessary and appropri
ate force against those nations, organizations, or persons he
determines planned, authorized, committed, or aided the
terrorist attacks . . . in order to prevent any future acts of
international terrorism against the United States by such
nations, organizations or persons.” Authorization for Use
of Military Force (AUMF), 115 Stat. 224, note following
50 U. S. C. § 1541 (2000 ed., Supp. III). Acting pursuant
to the AUMF, and having determined that the Taliban re
gime had supported al Qaeda, the President ordered the
Armed Forces of the United States to invade Afghanistan.
In the ensuing hostilities, hundreds of individuals, Hamdan
among them, were captured and eventually detained at
Guantanamo Bay.
On November 13, 2001, while the United States was still
engaged in active combat with the Taliban, the President
issued a comprehensive military order intended to govern
the “Detention, Treatment, and Trial of Certain Non-
Citizens in the War Against Terrorism,” 66 Fed. Reg. 57833
(hereinafter November 13 Order or Order). Those subject
to the November 13 Order include any noncitizen for whom
the President determines “there is reason to believe” that
he or she (1) “is or was” a member of al Qaeda or (2) has
engaged or participated in terrorist activities aimed at or
harmful to the United States. Id., at 57834. Any such indi
vidual “shall, when tried, be tried by military commission for
any and all offenses triable by military commission that such
individual is alleged to have committed, and may be punished
in accordance with the penalties provided under applicable
law, including life imprisonment or death.” Ibid. The No

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
569 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
vember 13 Order vested in the Secretary of Defense the
power to appoint military commissions to try individuals
subject to the Order, but that power has since been dele
gated to John D. Altenburg, Jr., a retired Army major gen
eral and longtime military lawyer who has been designated
“Appointing Authority for Military Commissions.”
On July 3, 2003, the President announced his determina
tion that Hamdan and five other detainees at Guantanamo
Bay were subject to the November 13 Order and thus triable
by military commission. In December 2003, military coun
sel was appointed to represent Hamdan. Two months later,
counsel filed demands for charges and for a speedy trial pur
suant to Article 10 of the UCMJ, 10 U. S. C. § 810. On Feb
ruary 23, 2004, the legal adviser to the Appointing Authority
denied the applications, ruling that Hamdan was not entitled
to any of the protections of the UCMJ. Not until July 13,
2004, after Hamdan had commenced this action in the United
States District Court for the Western District of Washing
ton, did the Government finally charge him with the offense
for which, a year earlier, he had been deemed eligible for
trial by military commission.
The charging document, which is unsigned, contains 13
numbered paragraphs. The first two paragraphs recite the
asserted bases for the military commission’s jurisdiction—
namely, the November 13 Order and the President’s July 3,
2003, declaration that Hamdan is eligible for trial by military
commission. The next nine paragraphs, collectively entitled
“General Allegations,” describe al Qaeda’s activities from its
inception in 1989 through 2001 and identify Usama bin Laden
as the group’s leader. Hamdan is not mentioned in these
paragraphs.
Only the final two paragraphs, entitled “Charge: Conspir
acy,” contain allegations against Hamdan. Paragraph 12
charges that “from on or about February 1996 to on or about
November 24, 2001,” Hamdan “willfully and knowingly

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
570 HAMDAN v. RUMSFELD
Opinion of the Court
joined an enterprise of persons who shared a common crimi
nal purpose and conspired and agreed with [named members
of al Qaeda] to commit the following offenses triable by mil
itary commission: attacking civilians; attacking civilian ob
jects; murder by an unprivileged belligerent; and terrorism.”
App. to Pet. for Cert. 65a. There is no allegation that Ham
dan had any command responsibilities, played a leadership
role, or participated in the planning of any activity.
Paragraph 13 lists four “overt acts” that Hamdan is al
leged to have committed sometime between 1996 and No
vember 2001 in furtherance of the “enterprise and conspir
acy”: (1) he acted as Usama bin Laden’s “bodyguard and
personal driver,” “believ[ing]” all the while that bin Laden
“and his associates were involved in” terrorist acts prior to
and including the attacks of September 11, 2001; (2) he ar
ranged for transportation of, and actually transported, weap
ons used by al Qaeda members and by bin Laden’s body
guards (Hamdan among them); (3) he “drove or accompanied
[U]sama bin Laden to various al Qaida-sponsored training
camps, press conferences, or lectures,” at which bin Laden
encouraged attacks against Americans; and (4) he received
weapons training at al Qaeda-sponsored camps. Id., at
65a–67a.
After this formal charge was filed, the United States Dis
trict Court for the Western District of Washington trans
erred Hamdan’s habeas and mandamus petitions to the
United States District Court for the District of Columbia.
Meanwhile, a Combatant Status Review Tribunal (CSRT)
convened pursuant to a military order issued on July 7, 2004,
decided that Hamdan’s continued detention at Guantanamo
Bay was warranted because he was an “enemy combatant.” 1
1 An “enemy combatant” is defined by the military order as “an individ
ual who was part of or supporting Taliban or al Qaeda forces, or associated
forces that are engaged in hostilities against the United States or its coali
tion partners.” Memorandum from Deputy Secretary of Defense Paul
Wolfowitz re: Order Establishing Combatant Status Review Tribunal

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
Cite as: 548 U. S. 557 (2006) 571
Opinion of the Court
Separately, proceedings before the military commission
commenced.
On November 8, 2004, however, the District Court granted
Hamdan’s petition for habeas corpus and stayed the commis
sion’s proceedings. It concluded that the President’s au
thority to establish military commissions extends only to “of
fenders or offenses triable by military [commission] under
the law of war,” 344 F. Supp. 2d, at 158; that the law of war
includes the Geneva Convention (III) Relative to the Treat
ment of Prisoners of War, Aug. 12, 1949, [1955] 6 U. S. T.
3316, T. I. A. S. No. 3364 (Third Geneva Convention); that
Hamdan is entitled to the full protections of the Third Ge
neva Convention until adjudged, in compliance with that
treaty, not to be a prisoner of war; and that, whether or not
Hamdan is properly classified as a prisoner of war, the mili
tary commission convened to try him was established in vio
lation of both the UCMJ and Common Article 3 of the Third
Geneva Convention because it had the power to convict
based on evidence the accused would never see or hear. 344
F. Supp. 2d, at 158–172.
The Court of Appeals for the District of Columbia Circuit
reversed. Like the District Court, the Court of Appeals de
clined the Government’s invitation to abstain from consider
ing Hamdan’s challenge. Cf. Schlesinger v. Councilman,
420 U. S. 738 (1975). On the merits, the panel rejected the
District Court’s further conclusion that Hamdan was entitled
to relief under the Third Geneva Convention. All three
judges agreed that the Geneva Conventions were not “judi
cially enforceable,” 415 F. 3d, at 38, and two thought that the
Conventions did not in any event apply to Hamdan, id., at
40–42; but see id., at 44 (Williams, J., concurring). In other
portions of its opinion, the court concluded that our decision
in Quirin foreclosed any separation-of-powers objection to
§ a (July 7, 2004), available at http://www.defenselink.mil/news/Jul2004/
d20040707review.pdf (all Internet materials as visited June 26, 2006, and
available in Clerk of Court’s case file).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
572 HAMDAN v. RUMSFELD
Opinion of the Court
the military commission’s jurisdiction, and held that Ham
dan’s trial before the contemplated commission would violate
neither the UCMJ nor U. S. Armed Forces regulations in
tended to implement the Geneva Conventions. 415 F. 3d, at
38, 42–43.
On November 7, 2005, we granted certiorari to decide
whether the military commission convened to try Hamdan
has authority to do so, and whether Hamdan may rely on the
Geneva Conventions in these proceedings.
II
On February 13, 2006, the Government filed a motion to
dismiss the writ of certiorari. The ground cited for dis
missal was the recently enacted Detainee Treatment Act of
2005 (DTA), Pub. L. 109–148, 119 Stat. 2739. We postponed
our ruling on that motion pending argument on the merits,
546 U. S. 1166 (2006), and now deny it.
The DTA, which was signed into law on December 30,
2005, addresses a broad swath of subjects related to detain
ees. It places restrictions on the treatment and interroga
tion of detainees in U. S. custody, and it furnishes procedural
protections for U. S. personnel accused of engaging in im
proper interrogation. DTA §§ 1002–1004, 119 Stat. 2739–
2740. It also sets forth certain “procedures for status
review of detainees outside the United States.”
§ 1005, id., at 2740. Subsections (a) through (d) of § 1005
direct the Secretary of Defense to report to Congress the
procedures being used by CSRTs to determine the proper
classification of detainees held in Guantanamo Bay, Iraq,
and Afghanistan, and to adopt certain safeguards as part of
those procedures.
Subsection (e) of § 1005, which is entitled “Judicial Re
view of Detention of Enemy Combatants,” supplies the
basis for the Government’s jurisdictional argument. The
subsection contains three numbered paragraphs. The first
paragraph amends the judicial code as follows:

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
573 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
“(1) In general.—Section 2241 of title 28, United
States Code, is amended by adding at the end the
following:
“ ‘(e) Except as provided in section 1005 of the De
tainee Treatment Act of 2005, no court, justice, or judge
shall have jurisdiction to hear or consider—
“ ‘(1) an application for a writ of habeas corpus filed
by or on behalf of an alien detained by the Department
of Defense at Guantanamo Bay, Cuba; or
“ ‘(2) any other action against the United States or its
agents relating to any aspect of the detention by the
Department of Defense of an alien at Guantanamo Bay,
Cuba, who—
“ ‘(A) is currently in military custody; or
“ ‘(B) has been determined by the United States
Court of Appeals for the District of Columbia Circuit in
accordance with the procedures set forth in section
1005(e) of the Detainee Treatment Act of 2005 to have
been properly detained as an enemy combatant. ’ ”
§ 1005(e), id., at 2741–2742.
Paragraph (2) of subsection (e) vests in the Court of Ap
peals for the District of Columbia Circuit the “exclusive ju
risdiction to determine the validity of any final decision of
a [CSRT] that an alien is properly detained as an enemy
combatant.” Paragraph (2) also delimits the scope of that
review. See §§ 1005(e)(2)(C)(i)–(ii), id., at 2742.
Paragraph (3) mirrors paragraph (2) in structure, but gov
erns judicial review of final decisions of military commis
sions, not CSRTs. It vests in the Court of Appeals for the
District of Columbia Circuit “exclusive jurisdiction to deter
mine the validity of any final decision rendered pursuant to
Military Commission Order No. 1, dated August 31, 2005 (or
any successor military order).” § 1005(e)(3)(A), id., at 2743.2
2 The military order referenced in this section is discussed further in
Parts III and VI, infra.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
574 HAMDAN v. RUMSFELD
Opinion of the Court
Review is as of right for any alien sentenced to death or a
term of imprisonment of 10 years or more, but is at the Court
of Appeals’ discretion in all other cases. The scope of re
view is limited to the following inquiries:
“(i) whether the final decision [of the military commis
sion] was consistent with the standards and procedures
specified in the military order referred to in subpara
graph (A); and
“(ii) to the extent the Constitution and laws of the
United States are applicable, whether the use of such
standards and procedures to reach the final decision is
consistent with the Constitution and laws of the United
States.” § 1005(e)(3)(D), ibid.
Finally, § 1005 contains an “effective date” provision,
which reads as follows:
“(1) In general.—This section shall take effect on
the date of the enactment of this Act.
“(2) Review of Combatant Status Tribunal and
Military Commission Decisions.—Paragraphs (2) and
(3) of subsection (e) shall apply with respect to any claim
whose review is governed by one of such paragraphs and
that is pending on or after the date of the enactment of
this Act.” § 1005(h), id., at 2743–2744.3
The DTA is silent about whether paragraph (1) of subsection
(e) “shall apply” to claims pending on the date of enactment.
The Government argues that §§ 1005(e)(1) and 1005(h) had
the immediate effect, upon enactment, of repealing federal
jurisdiction not just over detainee habeas actions yet to be
filed but also over any such actions then pending in any fed
eral court—including this Court. Accordingly, it argues, we
3 The penultimate subsections of § 1005 emphasize that the provision
does not “confer any constitutional right on an alien detained as an enemy
combatant outside the United States” and that the “United States” does
not, for purposes of § 1005, include Guantanamo Bay. §§ 1005(f)–(g).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
575 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
lack jurisdiction to review the Court of Appeals’ decision
below.
Hamdan objects to this theory on both constitutional and
statutory grounds. Principal among his constitutional argu
ments is that the Government’s preferred reading raises
grave questions about Congress’ authority to impinge upon
this Court’s appellate jurisdiction, particularly in habeas
cases. Support for this argument is drawn from Ex parte
Yerger, 8 Wall. 85 (1869), in which, having explained that
“the denial to this court of appellate jurisdiction” to consider
an original writ of habeas corpus would “greatly weaken the
efficacy of the writ,” id., at 102–103, we held that Congress
would not be presumed to have effected such denial absent
an unmistakably clear statement to the contrary. See id.,
at 104–105; see also Felker v. Turpin, 518 U. S. 651 (1996);
Durousseau v. United States, 6 Cranch 307, 314 (1810) (opin
ion for the Court by Marshall, C. J.) (The “appellate powers
of this court” are not created by statute but are “given by
the constitution”); United States v. Klein, 13 Wall. 128 (1872).
Cf. Ex parte McCardle, 7 Wall. 506, 514 (1869) (holding that
Congress had validly foreclosed one avenue of appellate re
view where its repeal of habeas jurisdiction, reproduced in
the margin,4 could not have been “a plainer instance of posi
tive exception”). Hamdan also suggests that, if the Govern
ment’s reading is correct, Congress has unconstitutionally
suspended the writ of habeas corpus.
We find it unnecessary to reach either of these arguments.
Ordinary principles of statutory construction suffice to rebut
4 “ ‘And be it further enacted, That so much of the act approved Febru
ary 5, 1867, entitled “An act to amend an act to establish the judicial courts
of the United States, approved September 24, 1789,” as authorized an ap
peal from the judgment of the Circuit Court to the Supreme Court of the
United States, or the exercise of any such jurisdiction by said Supreme
Court, on appeals which have been, or may hereafter be taken, be, and
the same is hereby repealed.’ ” 7 Wall., at 508.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
576 HAMDAN v. RUMSFELD
Opinion of the Court
the Government’s theory—at least insofar as this case, which
was pending at the time the DTA was enacted, is concerned.
The Government acknowledges that only paragraphs (2)
and (3) of subsection (e) are expressly made applicable to
pending cases, see § 1005(h)(2), 119 Stat. 2743–2744, but ar
gues that the omission of paragraph (1) from the scope of
that express statement is of no moment. This is so, we are
told, because Congress’ failure to expressly reserve federal
courts’ jurisdiction over pending cases erects a presumption
against jurisdiction, and that presumption is rebutted by nei
ther the text nor the legislative history of the DTA.
The first part of this argument is not entirely without sup
port in our precedents. We have in the past “applied inter
vening statutes conferring or ousting jurisdiction, whether
or not jurisdiction lay when the underlying conduct oc
curred or when the suit was filed.” Landgraf v. USI Film
Products, 511 U. S. 244, 274 (1994) (citing Bruner v. United
States, 343 U. S. 112 (1952); Hallowell v. Commons, 239 U. S.
506 (1916)); see Republic of Austria v. Altmann, 541 U. S.
677, 693 (2004). But the “presumption” that these cases
have applied is more accurately viewed as the nonapplication
of another presumption—viz., the presumption against ret
roactivity—in certain limited circumstances.5 If a statutory
provision “would operate retroactively” as applied to cases
pending at the time the provision was enacted, then “our
traditional presumption teaches that it does not govern
absent clear congressional intent favoring such a result.”
Landgraf, 511 U. S., at 280. We have explained, how
ever, that, unlike other intervening changes in the law, a
5 See Hughes Aircraft Co. v. United States ex rel. Schumer, 520 U. S.
939, 951 (1997) (“The fact that courts often apply newly enacted
jurisdiction-allocating statutes to pending cases merely evidences certain
limited circumstances failing to meet the conditions for our generally ap
plicable presumption against retroactivity . . . ”).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
577 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
jurisdiction-conferring or jurisdiction-stripping statute usu
ally “takes away no substantive right but simply changes the
tribunal that is to hear the case.” Hallowell, 239 U. S., at
508. If that is truly all the statute does, no retroactivity
problem arises because the change in the law does not “im
pair rights a party possessed when he acted, increase a par
ty’s liability for past conduct, or impose new duties with
respect to transactions already completed.” Landgraf, 511
U. S., at 280.6 And if a new rule has no retroactive effect,
the presumption against retroactivity will not prevent its ap
plication to a case that was already pending when the new
rule was enacted.
That does not mean, however, that all jurisdiction
stripping provisions—or even all such provisions that truly
lack retroactive effect—must apply to cases pending at the
time of their enactment.7 “[N]ormal rules of construction,”
including a contextual reading of the statutory language,
may dictate otherwise. Lindh v. Murphy, 521 U. S. 320, 326
6 Cf. ibid. (“Statutes merely addressing which court shall have jurisdic
tion to entertain a particular cause of action can fairly be said merely to
regulate the secondary conduct of litigation and not the underlying pri
mary conduct of the parties” (emphasis in original)).
7 In his insistence to the contrary, Justice Scalia reads too much into
Bruner v. United States, 343 U. S. 112 (1952), Hallowell v. Commons, 239
U. S. 506 (1916), and Insurance Co. v. Ritchie, 5 Wall. 541 (1867). See
post, at 656–658 (dissenting opinion). None of those cases says that the
absence of an express provision reserving jurisdiction over pending cases
trumps or renders irrelevant any other indications of congressional intent.
Indeed, Bruner itself relied on such other indications—including a nega
tive inference drawn from the statutory text, cf. infra, at 578—to support
its conclusion that jurisdiction was not available. The Court observed
that (1) Congress had been put on notice by prior lower court cases ad
dressing the Tucker Act that it ought to specifically reserve jurisdiction
over pending cases, see 343 U. S., at 115, and (2) in contrast to the congres
sional silence concerning reservation of jurisdiction, reservation had been
made of “ ‘any rights or liabilities’ existing at the effective date of the Act”
repealed by another provision of the Act, ibid., n. 7.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
578 HAMDAN v. RUMSFELD
Opinion of the Court
(1997).8 A familiar principle of statutory construction, rele
vant both in Lindh and here, is that a negative inference may
be drawn from the exclusion of language from one statutory
provision that is included in other provisions of the same
statute. See id., at 330; see also, e. g., Russello v. United
States, 464 U. S. 16, 23 (1983) (“ ‘[W]here Congress includes
particular language in one section of a statute but omits it
in another section of the same Act, it is generally presumed
that Congress acts intentionally and purposely in the dispar
ate inclusion or exclusion’ ”). The Court in Lindh relied on
this reasoning to conclude that certain limitations on the
availability of habeas relief imposed by AEDPA applied only
to cases filed after that statute’s effective date. Congress’
failure to identify the temporal reach of those limitations,
which governed noncapital cases, stood in contrast to its ex
press command in the same legislation that new rules gov
erning habeas petitions in capital cases “apply to cases pend
ing on or after the date of enactment.” § 107(c), 110 Stat.
1226; see Lindh, 521 U. S., at 329–330. That contrast, com
bined with the fact that the amendments at issue “affect[ed]
substantive entitlement to relief,” id., at 327, warranted
drawing a negative inference.
A like inference follows a fortiori from Lindh in this case.
“If . . . Congress was reasonably concerned to ensure that
[§§ 1005(e)(2) and (3)] be applied to pending cases, it should
have been just as concerned about [§ 1005(e)(1)], unless it had
the different intent that the latter [section] not be applied to
the general run of pending cases.” Id., at 329. If anything,
the evidence of deliberate omission is stronger here than it
8 The question in Lindh was whether new limitations on the availability
of habeas relief imposed by the Antiterrorism and Effective Death Penalty
Act of 1996 (AEDPA), 110 Stat. 1214, applied to habeas actions pending
on the date of AEDPA’s enactment. We held that they did not. At the
outset, we rejected the State’s argument that, in the absence of a clear
congressional statement to the contrary, a “procedural” rule must apply
to pending cases. 521 U. S., at 326.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
579 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
was in Lindh. In Lindh, the provisions to be contrasted had
been drafted separately but were later “joined together and
. . . considered simultaneously when the language raising the
implication was inserted.” Id., at 330. We observed that
Congress’ tandem review and approval of the two sets of
provisions strengthened the presumption that the relevant
omission was deliberate. Id., at 331; see also Field v. Mans,
516 U. S. 59, 75 (1995) (“The more apparently deliberate the
contrast, the stronger the inference, as applied, for example,
to contrasting statutory sections originally enacted simulta
neously in relevant respects”). Here, Congress not only
considered the respective temporal reaches of paragraphs
(1), (2), and (3) of subsection (e) together at every stage, but
omitted paragraph (1) from its directive that paragraphs
(2) and (3) apply to pending cases only after having rejected
earlier proposed versions of the statute that would have in
cluded what is now paragraph (1) within the scope of that
directive. Compare DTA § 1005(h)(2), 119 Stat. 2743–2744,
with 151 Cong. Rec. S12655 (Nov. 10, 2005) (S. Amdt. 2515);
see id., at S14257–S14258 (Dec. 21, 2005) (discussing similar
language proposed in both the House and the Senate).9
Congress’ rejection of the very language that would have
9 That paragraph (1), along with paragraphs (2) and (3), is to “take effect
on the date of the enactment,” DTA § 1005(h)(1), 119 Stat. 2743, is not
dispositive; “a ‘statement that a statute will become effective on a certain
date does not even arguably suggest that it has any application to conduct
that occurred at an earlier date.’ ” INS v. St. Cyr, 533 U. S. 289, 317 (2001)
(quoting Landgraf v. USI Film Products, 511 U. S. 244, 257 (1994)). Cer
tainly, the “effective date” provision cannot bear the weight Justice
Scalia would place on it. See post, at 659, and n. 1. Congress deemed
that provision insufficient, standing alone, to render subsections (e)(2) and
(e)(3) applicable to pending cases; hence its adoption of subsection (h)(2).
Justice Scalia seeks to avoid reducing subsection (h)(2) to a mere redun
dancy—a consequence he seems to acknowledge must otherwise follow
from his interpretation—by speculating that Congress had special reasons,
not also relevant to subsection (e)(1), to worry that subsections (e)(2) and
(e)(3) would be ruled inapplicable to pending cases. As we explain infra,
at 582–583, and n. 12, that attempt fails.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
580 HAMDAN v. RUMSFELD
Opinion of the Court
achieved the result the Government urges here weighs heav
ily against the Government’s interpretation. See Doe v.
Chao, 540 U. S. 614, 621–623 (2004).10
10 We note that statements made by Senators preceding passage of the
DTA lend further support to what the text of the DTA and its drafting
history already make plain. Senator Levin, one of the sponsors of the
final bill, objected to earlier versions of the DTA’s “effective date” provi
sion that would have made subsection (e)(1) applicable to pending cases.
See, e. g., 151 Cong. Rec. S12667 (Nov. 10, 2005) (amendment proposed
by Sen. Graham that would have rendered what is now subsection (e)(1)
applicable to “any application or other action that is pending on or after
the date of the enactment of this Act”). Senator Levin urged adoption of
an alternative amendment that “would apply only to new habeas cases
filed after the date of enactment.” Id., at S12802 (Nov. 15, 2005). That
alternative amendment became the text of subsection (h)(2). (In light of
the extensive discussion of the DTA’s effect on pending cases prior to
passage of the DTA, see, e. g., id., at S12664 (Nov. 10, 2005); id., at S12755
(Nov. 14, 2005); id., at S12799–S12802 (Nov. 15, 2005); id., at S14245,
S14252–S14253, S14257–S14258, S14274–S14275 (Dec. 21, 2005), it cannot
be said that the changes to subsection (h)(2) were inconsequential.
Cf. post, at 668 (Scalia, J., dissenting).)
While statements attributed to the final bill’s two other sponsors, Sena
tors Graham and Kyl, arguably contradict Senator Levin’s contention that
the final version of the DTA preserved jurisdiction over pending habeas
cases, see 151 Cong. Rec. S14263–S14264 (Dec. 21, 2005), those statements
appear to have been inserted into the Congressional Record after the Sen
ate debate. See Reply Brief for Petitioner 5, n. 6; see also 151 Cong. Rec.
S14260 (statement of Sen. Kyl) (“I would like to say a few words about the
now-completed National Defense Authorization Act for fiscal year 2006”
(emphasis added)). All statements made during the debate itself support
Senator Levin’s understanding that the final text of the DTA would not
render subsection (e)(1) applicable to pending cases. See, e. g., id., at
S14245, S14252–S14253, S14274–S14275 (Dec. 21, 2005). The statements
that Justice Scalia cites as evidence to the contrary construe subsection
(e)(3) to strip this Court of jurisdiction, see post, at 666, n. 4 (dissenting
opinion) (quoting 151 Cong. Rec. S12796 (Nov. 15, 2005) (statement of Sen.
Specter))—a construction that the Government has expressly disavowed
in this litigation, see n. 11, infra. The inapposite November 14, 2005,
statement of Senator Graham, which Justice Scalia cites as evidence of
that Senator’s “assumption that pending cases are covered,” post, at 666,

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
581 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
The Government nonetheless offers two reasons why, in
its view, no negative inference may be drawn in favor of ju
risdiction. First, it asserts that Lindh is inapposite because
“Section 1005(e)(1) and (h)(1) remove jurisdiction, while Sec
tion 1005(e)(2), (3) and (h)(2) create an exclusive review
mechanism and define the nature of that review.” Reply
Brief in Support of Respondents’ Motion to Dismiss 4. Be
cause the provisions being contrasted “address wholly dis
tinct subject matters,” Martin v. Hadix, 527 U. S. 343, 356
(1999), the Government argues, Congress’ different treat
ment of them is of no significance.
This argument must fail because it rests on a false distinc
tion between the “jurisdictional” nature of subsection (e)(1)
and the “procedural” character of subsections (e)(2) and
(e)(3). In truth, all three provisions govern jurisdiction over
detainees’ claims; subsection (e)(1) addresses jurisdiction in
habeas cases and other actions “relating to any aspect of the
detention,” while subsections (e)(2) and (e)(3) vest exclu
sive,11 but limited, jurisdiction in the Court of Appeals for
the District of Columbia Circuit to review “final decision[s]”
of CSRTs and military commissions.
That subsection (e)(1) strips jurisdiction while subsections
(e)(2) and (e)(3) restore it in limited form is hardly a distinc
tion upon which a negative inference must founder. Jus
tice Scalia, in arguing to the contrary, maintains that Con
and n. 3 (citing 151 Cong. Rec. S12756 (Nov. 14, 2005)), follows directly
after the uncontradicted statement of his cosponsor, Senator Levin, as
suring members of the Senate that “the amendment will not strip the
courts of jurisdiction over [pending] cases,” id., at S12755.
11 The District of Columbia Circuit’s jurisdiction, while “exclusive” in
one sense, would not bar this Court’s review on appeal from a decision
under the DTA. See Reply Brief in Support of Respondents’ Motion to
Dismiss 16–17, n. 12 (“While the DTA does not expressly call for Supreme
Court review of the District of Columbia Circuit’s decisions, Section[s]
1005(e)(2) and (3) . . . do not remove this Court’s jurisdiction over such
decisions under 28 U. S. C. § 1254(1)”).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
582 HAMDAN v. RUMSFELD
Opinion of the Court
gress had “ample reason” to provide explicitly for application
of subsections (e)(2) and (e)(3) to pending cases because
“jurisdiction-ousting” provisions like subsection (e)(1) have
been treated differently under our retroactivity jurispru
dence than “jurisdiction-creating” ones like subsections
(e)(2) and (e)(3). Post, at 662 (dissenting opinion); see also
Reply Brief in Support of Respondents’ Motion to Dismiss
5–6. That theory is insupportable. Assuming, arguendo,
that subsections (e)(2) and (e)(3) “confer new jurisdiction (in
the D. C. Circuit) where there was none before,” post, at 662
(emphasis in original); but see Rasul v. Bush, 542 U. S. 466
(2004), and that our precedents can be read to “strongly indi
cat[e]” that jurisdiction-creating statutes raise special retro
activity concerns not also raised by jurisdiction-stripping
statutes, post, at 662,12 subsections (e)(2) and (e)(3) “confer”
jurisdiction in a manner that cannot conceivably give rise to
retroactivity questions under our precedents. The provi
sions impose no additional liability or obligation on any pri
vate party or even on the United States, unless one counts
the burden of litigating an appeal—a burden not a single
one of our cases suggests triggers retroactivity concerns.13
12 This assertion is itself highly questionable. The cases that Justice
Scalia cites to support his distinction are Republic of Austria v. Alt
mann, 541 U. S. 677 (2004), and Hughes Aircraft Co. v. United States ex
rel. Schumer, 520 U. S. 939 (1997). See post, at 662. While the Court in
both of those cases recognized that statutes “creating” jurisdiction may
have retroactive effect if they affect “substantive” rights, see Altmann,
541 U. S., at 695, and n. 15; Hughes Aircraft, 520 U. S., at 951, we have
applied the same analysis to statutes that have jurisdiction-stripping ef
fect, see Lindh v. Murphy, 521 U. S. 320, 327–328 (1997); id., at 342–343
(Rehnquist, C. J., dissenting) (construing AEDPA’s amendments as “oust
ing jurisdiction”).
13 See Landgraf, 511 U. S., at 271, n. 25 (observing that “the great major
ity of our decisions relying upon the antiretroactivity presumption have
involved intervening statutes burdening private parties,” though “we have
applied the presumption in cases involving new monetary obligations that
fell only on the government” (emphasis added)); see also Altmann, 541
U. S., at 728–729 (Kennedy, J., dissenting) (explaining that if retroactivity

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
583 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
Moreover, it strains credulity to suggest that the desire to
reinforce the application of subsections (e)(2) and (e)(3) to
pending cases drove Congress to exclude subsection (e)(1)
from § 1005(h)(2).
The Government’s second objection is that applying
subsections (e)(2) and (e)(3) but not (e)(1) to pending cases
“produces an absurd result” because it grants (albeit only
temporarily) dual jurisdiction over detainees’ cases in cir
cumstances where the statute plainly envisions that the D. C.
Circuit will have “exclusive” and immediate jurisdiction over
such cases. Reply Brief in Support of Respondents’ Motion
to Dismiss 7. But the premise here is faulty; subsections
(e)(2) and (e)(3) grant jurisdiction only over actions to “deter
mine the validity of any final decision” of a CSRT or commis
sion. Because Hamdan, at least, is not contesting any “final
decision” of a CSRT or military commission, his action does
not fall within the scope of subsection (e)(2) or (e)(3). There
is, then, no absurdity.14
The Government’s more general suggestion that Congress
can have had no good reason for preserving habeas jurisdic
tion over cases that had been brought by detainees prior to
enactment of the DTA not only is belied by the legislative
history, see n. 10, supra, but is otherwise without merit.
There is nothing absurd about a scheme under which pend
ing habeas actions—particularly those, like this one, that
challenge the very legitimacy of the tribunals whose judg
ments Congress would like to have reviewed—are pre
served, and more routine challenges to final decisions ren
concerns do not arise when a new monetary obligation is imposed on the
United States it is because “Congress, by virtue of authoring the legisla
tion, is itself fully capable of protecting the Federal Government from
having its rights degraded by retroactive laws”).
14 There may be habeas cases that were pending in the lower courts at
the time the DTA was enacted that do qualify as challenges to “final deci
sion[s]” within the meaning of subsection (e)(2) or (e)(3). We express no
view about whether the DTA would require transfer of such an action to
the D. C. Circuit.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
584 HAMDAN v. RUMSFELD
Opinion of the Court
dered by those tribunals are carefully channeled to a par
ticular court and through a particular lens of review.
Finally, we cannot leave unaddressed Justice Scalia’s
contentions that the “meaning of § 1005(e)(1) is entirely clear,”
post, at 660, and that “the plain import of a statute re
pealing jurisdiction is to eliminate the power to consider
and render judgment—in an already pending case no less than
in a case yet to be filed,” post, at 657 (emphasis in original).
Only by treating the Bruner rule as an inflexible trump (a
thing it has never been, see n. 7, supra) and ignoring both
the rest of § 1005’s text and its drafting history can one
conclude as much. Congress here expressly provided that
subsections (e)(2) and (e)(3) applied to pending cases. It
chose not to so provide—after having been presented with the
option—for subsection (e)(1). The omission is an integral
part of the statutory scheme that muddies whatever “plain
meaning” may be discerned from blinkered study of sub
section (e)(1) alone. The dissent’s speculation about what
Congress might have intended by the omission not only is
counterfactual, cf. n. 10, supra (recounting legislative history),
but rests on both a misconstruction of the DTA and an errone
ous view of our precedents, see supra, at 582–583, and n. 12.
For these reasons, we deny the Government’s motion to
dismiss.15
III
Relying on our decision in Councilman, 420 U. S. 738, the
Government argues that, even if we have statutory jurisdic
15 Because we conclude that § 1005(e)(1) does not strip federal courts’
jurisdiction over cases pending on the date of the DTA’s enactment, we do
not decide whether, if it were otherwise, this Court would nonetheless
retain jurisdiction to hear Hamdan’s appeal. Cf. supra, at 575. Nor do
we decide the manner in which the canon of constitutional avoidance
should affect subsequent interpretation of the DTA. See, e. g., St. Cyr,
533 U. S., at 300 (a construction of a statute “that would entirely preclude
review of a pure question of law by any court would give rise to substan
tial constitutional questions”).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
585 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
tion, we should apply the “judge-made rule that civilian
courts should await the final outcome of on-going military
proceedings before entertaining an attack on those proceed
ings.” Brief for Respondents 12. Like the District Court
and the Court of Appeals before us, we reject this argument.
In Councilman, an army officer on active duty was re
ferred to a court-martial for trial on charges that he violated
the UCMJ by selling, transferring, and possessing mari
juana. 420 U. S., at 739–740. Objecting that the alleged of
fenses were not “ ‘service connected,’ ” id., at 740, the officer
filed suit in Federal District Court to enjoin the proceedings.
He neither questioned the lawfulness of courts-martial or
their procedures nor disputed that, as a serviceman, he was
subject to court-martial jurisdiction. His sole argument
was that the subject matter of his case did not fall within
the scope of court-martial authority. See id., at 741, 759.
The District Court granted his request for injunctive relief,
and the Court of Appeals affirmed.
We granted certiorari and reversed. Id., at 761. We did
not reach the merits of whether the marijuana charges were
sufficiently “service connected” to place them within the
subject-matter jurisdiction of a court-martial. Instead, we
concluded that, as a matter of comity, federal courts should
normally abstain from intervening in pending court-martial
proceedings against members of the Armed Forces,16 and
16 Councilman distinguished service personnel from civilians, whose
challenges to ongoing military proceedings are cognizable in federal court.
See, e. g., United States ex rel. Toth v. Quarles, 350 U. S. 11 (1955). As
we explained in Councilman, abstention is not appropriate in cases in
which individuals raise “ ‘substantial arguments denying the right of the
military to try them at all,’ ” and in which the legal challenge “turn[s] on
the status of the persons as to whom the military asserted its power.”
420 U. S., at 759 (quoting Noyd v. Bond, 395 U. S. 683, 696, n. 8 (1969)).
In other words, we do not apply Councilman abstention when there is a
substantial question whether a military tribunal has personal jurisdiction
over the defendant. Because we conclude that abstention is inappropriate

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
586 HAMDAN v. RUMSFELD
Opinion of the Court
further that there was nothing in the particular circum
stances of the officer’s case to displace that general rule.
See id., at 740, 758.
Councilman identifies two considerations of comity that
together favor abstention pending completion of ongoing
court-martial proceedings against service personnel. See
New v. Cohen, 129 F. 3d 639, 643 (CADC 1997); see also 415
F. 3d, at 36–37 (discussing Councilman and New). First,
military discipline and, therefore, the efficient operation of
the Armed Forces are best served if the military justice sys
tem acts without regular interference from civilian courts.
See Councilman, 420 U. S., at 752. Second, federal courts
should respect the balance that Congress struck between
military preparedness and fairness to individual service
members when it created “an integrated system of military
courts and review procedures, a critical element of which is
the Court of Military Appeals consisting of civilian judges
‘completely removed from all military influence or per
suasion . . . .’ ” Id., at 758 (quoting H. R. Rep. No. 491,
81st Cong., 1st Sess., 7 (1949)). Just as abstention in the
face of ongoing state criminal proceedings is justified by our
expectation that state courts will enforce federal rights, so
abstention in the face of ongoing court-martial proceedings
is justified by our expectation that the military court system
established by Congress—with its substantial procedural
protections and provision for appellate review by independ
ent civilian judges—“will vindicate servicemen’s constitu
tional rights,” 420 U. S., at 758. See id., at 755–758.17
for a more basic reason, we need not consider whether the jurisdictional
exception recognized in Councilman applies here.
17 See also Noyd, 395 U. S., at 694–696 (noting that the Court of Military
Appeals consisted of “disinterested civilian judges,” and concluding that
there was no reason for the Court to address an Air Force Captain’s argu
ment that he was entitled to remain free from confinement pending appeal
of his conviction by court-martial “when the highest military court stands
ready to consider petitioner’s arguments”). Cf. Parisi v. Davidson, 405

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
587 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
The same cannot be said here; indeed, neither of the com
ity considerations identified in Councilman weighs in favor
of abstention in this case. First, Hamdan is not a member
of our Nation’s Armed Forces, so concerns about military
discipline do not apply. Second, the tribunal convened to try
Hamdan is not part of the integrated system of military
courts, complete with independent review panels, that Con
gress has established. Unlike the officer in Councilman,
Hamdan has no right to appeal any conviction to the civilian
judges of the Court of Military Appeals (now called the
United States Court of Appeals for the Armed Forces, see
§ 924, 108 Stat. 2831). Instead, under Dept. of Defense Mili
tary Commission Order No. 1 (Commission Order No. 1),
App. C to Brief for Petitioner 46a, which was issued by the
Secretary of Defense on March 21, 2002, and amended most
recently on August 31, 2005, and which governs the proce
dures for Hamdan’s commission, any conviction would be re
viewed by a panel consisting of three military officers desig
nated by the Secretary. Id., § 6(H)(4). Commission Order
No. 1 provides that appeal of a review panel’s decision may
be had only to the Secretary himself, § 6(H)(5), and then,
finally, to the President, § 6(H)(6).18
We have no doubt that the various individuals assigned
review power under Commission Order No. 1 would strive
to act impartially and ensure that Hamdan receive all protec
tions to which he is entitled. Nonetheless, these review
bodies clearly lack the structural insulation from military
influence that characterizes the Court of Appeals for the
U. S. 34, 41–43 (1972) (“Under accepted principles of comity, the court
should stay its hand only if the relief the petitioner seeks . . . would also
be available to him with reasonable promptness and certainty through the
machinery of the military judicial system in its processing of the court
martial charge”).
18 If he chooses, the President may delegate this ultimate decision
making authority to the Secretary of Defense. See § 6(H)(6).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
588 HAMDAN v. RUMSFELD
Opinion of the Court
Armed Forces, and thus bear insufficient conceptual simi
larity to state courts to warrant invocation of abstention
principles.19
In sum, neither of the two comity considerations underly
ing our decision to abstain in Councilman applies to the cir
cumstances of this case. Instead, this Court’s decision in
Quirin is the most relevant precedent. In Quirin, eight
German saboteurs were captured upon arrival by submarine
in New York and Florida. 317 U. S., at 21. The President
convened a military commission to try seven of the sabo
teurs, who then filed habeas corpus petitions in the United
States District Court for the District of Columbia challeng
ing their trial by commission. We granted the saboteurs’
petition for certiorari to the Court of Appeals before judg
ment. See id., at 19. Far from abstaining pending the con
clusion of military proceedings, which were ongoing, we con
vened a special Term to hear the case and expedited our
review. That course of action was warranted, we explained,
“[i]n view of the public importance of the questions raised
by [the cases] and of the duty which rests on the courts, in
time of war as well as in time of peace, to preserve un
impaired the constitutional safeguards of civil liberty, and
because in our opinion the public interest required that we
consider and decide those questions without any avoidable
delay.” Ibid.
As the Court of Appeals here recognized, Quirin “pro
vides a compelling historical precedent for the power of civil
ian courts to entertain challenges that seek to interrupt the
19 Justice Scalia chides us for failing to include the D. C. Circuit’s
review powers under the DTA in our description of the review mechanism
erected by Commission Order No. 1. See post, at 675. Whether or not
the limited review permitted under the DTA may be treated as akin to the
plenary review exercised by the Court of Appeals for the Armed Forces,
petitioner here is not afforded a right to such review. See infra, at 616;
§ 1005(e)(3), 119 Stat. 2743.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
589 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
processes of military commissions.” 415 F. 3d, at 36.20 The
circumstances of this case, like those in Quirin, simply do not
implicate the “obligations of comity” that, under appropriate
circumstances, justify abstention. Quackenbush v. Allstate
Ins. Co., 517 U. S. 706, 733 (1996) (Kennedy, J., concurring).
Finally, the Government has identified no other “impor
tant countervailing interest” that would permit federal
courts to depart from their general “duty to exercise the
jurisdiction that is conferred upon them by Congress.” Id.,
at 716 (majority opinion). To the contrary, Hamdan and the
Government both have a compelling interest in knowing in
advance whether Hamdan may be tried by a military com
mission that arguably is without any basis in law and oper
20 Having correctly declined to abstain from addressing Hamdan’s chal
lenge to the lawfulness of the military commission convened to try him,
the Court of Appeals suggested that Councilman abstention nonetheless
applied to bar its consideration of one of Hamdan’s arguments—namely,
that his commission violated Article 3 of the Third Geneva Convention, 6
U. S. T. 3316, 3318. See Part VI, infra. Although the Court of Appeals
rejected the Article 3 argument on the merits, it also stated that, because
the challenge was not “jurisdictional,” it did not fall within the exception
that Schlesinger v. Councilman, 420 U. S. 738 (1975), recognized for de
fendants who raise substantial arguments that a military tribunal lacks
personal jurisdiction over them. See 415 F. 3d, at 42.
In reaching this conclusion, the Court of Appeals conflated two distinct
inquiries: (1) whether Hamdan has raised a substantial argument that the
military commission lacks authority to try him; and, more fundamentally,
(2) whether the comity considerations underlying Councilman apply to
trigger the abstention principle in the first place. As the Court of Ap
peals acknowledged at the beginning of its opinion, the first question war
rants consideration only if the answer to the second is yes. See 415 F. 3d,
at 36–37. Since, as the Court of Appeals properly concluded, the answer
to the second question is in fact no, there is no need to consider any
exception.
At any rate, it appears that the exception would apply here. As dis
cussed in Part VI, infra, Hamdan raises a substantial argument that, be
cause the military commission that has been convened to try him is not a
“ ‘regularly constituted court’ ” under the Geneva Conventions, it is ultra
vires and thus lacks jurisdiction over him. Brief for Petitioner 5.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
590 HAMDAN v. RUMSFELD
Opinion of the Court
ates free from many of the procedural rules prescribed by
Congress for courts-martial—rules intended to safeguard
the accused and ensure the reliability of any conviction.
While we certainly do not foreclose the possibility that ab
stention may be appropriate in some cases seeking review of
ongoing military commission proceedings (such as military
commissions convened on the battlefield), the foregoing dis
cussion makes clear that, under our precedent, abstention is
not justified here. We therefore proceed to consider the
merits of Hamdan’s challenge.
IV
The military commission, a tribunal neither mentioned in
the Constitution nor created by statute, was born of military
necessity. See W. Winthrop, Military Law and Precedents
831 (rev. 2d ed. 1920) (hereinafter Winthrop). Though fore
shadowed in some respects by earlier tribunals like the
Board of General Officers that General Washington convened
to try British Major John Andre´ for spying during the Revo
lutionary War, the commission “as such” was inaugurated in
1847. Id., at 832; G. Davis, A Treatise on the Military Law
of the United States 308 (rev. 3d ed. 1915) (hereinafter
Davis). As commander of occupied Mexican territory, and
having available to him no other tribunal, General Winfield
Scott that year ordered the establishment of both “ ‘military
commissions’ ” to try ordinary crimes committed in the occu
pied territory and a “council of war” to try offenses against
the law of war. Winthrop 832 (emphasis in original).
When the exigencies of war next gave rise to a need for
use of military commissions, during the Civil War, the dual
system favored by General Scott was not adopted. Instead,
a single tribunal often took jurisdiction over ordinary
crimes, war crimes, and breaches of military orders alike.
As further discussed below, each aspect of that seemingly
broad jurisdiction was in fact supported by a separate mili
tary exigency. Generally, though, the need for military com

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
591 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
missions during this period—as during the Mexican War—
was driven largely by the then very limited jurisdiction of
courts-martial: “The occasion for the military commission
arises principally from the fact that the jurisdiction of the
court-martial proper, in our law, is restricted by statute al
most exclusively to members of the military force and to cer
tain specific offences defined in a written code.” Id., at 831
(emphasis in original).
Exigency alone, of course, will not justify the establish
ment and use of penal tribunals not contemplated by Article
I, § 8, and Article III, § 1, of the Constitution unless some
other part of that document authorizes a response to the felt
need. See Ex parte Milligan, 4 Wall. 2, 121 (1866) (“Cer
tainly no part of the judicial power of the country was con
ferred on [military commissions]”); Ex parte Vallandigham,
1 Wall. 243, 251 (1864); see also Quirin, 317 U. S., at 25 (“Con
gress and the President, like the courts, possess no power
not derived from the Constitution”). And that authority, if
it exists, can derive only from the powers granted jointly to
the President and Congress in time of war. See id., at
26–29; In re Yamashita, 327 U. S. 1, 11 (1946).
The Constitution makes the President the “Commander in
Chief ” of the Armed Forces, Art. II, § 2, cl. 1, but vests in
Congress the powers to “declare War . . . and make Rules
concerning Captures on Land and Water,” Art. I, § 8, cl. 11,
to “raise and support Armies,” id., cl. 12, to “define and pun
ish . . . Offences against the Law of Nations,” id., cl. 10, and
“To make Rules for the Government and Regulation of the
land and naval Forces,” id., cl. 14. The interplay between
these powers was described by Chief Justice Chase in the
seminal case of Ex parte Milligan:
“The power to make the necessary laws is in Congress;
the power to execute in the President. Both powers
imply many subordinate and auxiliary powers. Each
includes all authorities essential to its due exercise.
But neither can the President, in war more than in

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
592 HAMDAN v. RUMSFELD
Opinion of the Court
peace, intrude upon the proper authority of Congress,
nor Congress upon the proper author ity of the
President. . . . Congress cannot direct the conduct of
campaigns, nor can the President, or any commander
under him, without the sanction of Congress, institute
tribunals for the trial and punishment of offences, either
of soldiers or civilians, unless in cases of a controlling
necessity, which justifies what it compels, or at least in
sures acts of indemnity from the justice of the legisla
ture.” 4 Wall., at 139–140.21
Whether Chief Justice Chase was correct in suggesting
that the President may constitutionally convene military
commissions “without the sanction of Congress” in cases of
“controlling necessity” is a question this Court has not an
swered definitively, and need not answer today. For we held
in Quirin that Congress had, through Article of War 15,
sanctioned the use of military commissions in such circum
stances. 317 U. S., at 28 (“By the Articles of War, and espe
cially Article 15, Congress has explicitly provided, so far as
it may constitutionally do so, that military tribunals shall
have jurisdiction to try offenders or offenses against the law
of war in appropriate cases”). Article 21 of the UCMJ, the
language of which is substantially identical to the old Article
15 and was preserved by Congress after World War II,22
reads as follows:
21 See also Winthrop 831 (“[I]n general, it is those provisions of the Con
stitution which empower Congress to ‘declare war’ and ‘raise armies,’ and
which, in authorizing the initiation of war, authorize the employment of
all necessary and proper agencies for its due prosecution, from which this
tribunal derives its original sanction” (emphasis in original)).
22 Article 15 was first adopted as part of the Articles of War in 1916.
See Act of Aug. 29, 1916, ch. 418, § 3, Art. 15, 39 Stat. 652. When the
Articles of War were codified and reenacted as the UCMJ in 1950, Con
gress determined to retain Article 15 because it had been “construed by
the Supreme Court (Ex Parte Quirin, 317 U. S. 1 (1942)).” S. Rep.
No. 486, 81st Cong., 1st Sess., 13 (1949).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
593 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
“Jurisdiction of courts-martial not exclusive.
“The provisions of this code conferring jurisdiction upon
courts-martial shall not be construed as depriving mili
tary commissions, provost courts, or other military tri
bunals of concurrent jurisdiction in respect of offenders
or offenses that by statute or by the law of war may be
tried by such military commissions, provost courts, or
other military tribunals.” 64 Stat. 115.
We have no occasion to revisit Quirin’s controversial char
acterization of Article of War 15 as congressional authoriza
tion for military commissions. Cf. Brief for Legal Scholars
and Historians as Amici Curiae 12–15. Contrary to the
Government’s assertion, however, even Quirin did not view
the authorization as a sweeping mandate for the President
to “invoke military commissions when he deems them nec
essary.” Brief for Respondents 17. Rather, the Quirin
Court recognized that Congress had simply preserved what
power, under the Constitution and the common law of war,
the President had had before 1916 to convene military com
missions—with the express condition that the President and
those under his command comply with the law of war. See
317 U. S., at 28–29.23 That much is evidenced by the Court’s
inquiry, following its conclusion that Congress had author
ized military commissions, into whether the law of war had
indeed been complied with in that case. See ibid.
The Government would have us dispense with the inquiry
that the Quirin Court undertook and find in either the
AUMF or the DTA specific, overriding authorization for the
very commission that has been convened to try Hamdan.
Neither of these congressional Acts, however, expands the
23 Whether or not the President has independent power, absent congres
sional authorization, to convene military commissions, he may not disre
gard limitations that Congress has, in proper exercise of its own war pow
ers, placed on his powers. See Youngstown Sheet & Tube Co. v. Sawyer,
343 U. S. 579, 637 (1952) (Jackson, J., concurring). The Government does
not argue otherwise.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
594 HAMDAN v. RUMSFELD
Opinion of the Court
President’s authority to convene military commissions.
First, while we assume that the AUMF activated the Presi
dent’s war powers, see Hamdi v. Rumsfeld, 542 U. S. 507
(2004) (plurality opinion), and that those powers include the
authority to convene military commissions in appropriate cir
cumstances, see id., at 518; Quirin, 317 U. S., at 28–29; see
also Yamashita, 327 U. S., at 11, there is nothing in the text
or legislative history of the AUMF even hinting that Con
gress intended to expand or alter the authorization set forth
in Article 21 of the UCMJ. Cf. Yerger, 8 Wall., at 105 (“Re
peals by implication are not favored”).24
Likewise, the DTA cannot be read to authorize this com
mission. Although the DTA, unlike either Article 21 or the
AUMF, was enacted after the President had convened Ham
dan’s commission, it contains no language authorizing that
tribunal or any other at Guantanamo Bay. The DTA obvi
ously “recognize[s]” the existence of the Guantanamo Bay
commissions in the weakest sense, Brief for Respondents 15,
because it references some of the military orders governing
them and creates limited judicial review of their “final deci
sion[s],” DTA § 1005(e)(3), 119 Stat. 2743. But the statute
also pointedly reserves judgment on whether “the Constitu
tion and laws of the United States are applicable” in review
ing such decisions and whether, if they are, the “standards
and procedures” used to try Hamdan and other detainees
actually violate the “Constitution and laws.” Ibid.
Together, the UCMJ, the AUMF, and the DTA at most
acknowledge a general Presidential authority to convene mil
24 On this point, it is noteworthy that the Court in Ex parte Quirin, 317
U. S. 1 (1942), looked beyond Congress’ declaration of war and accompany
ing authorization for use of force during World War II, and relied instead
on Article of War 15 to find that Congress had authorized the use of mili
tary commissions in some circumstances. See id., at 26–29. Justice
Thomas’ assertion that we commit “error” in reading Article 21 of the
UCMJ to place limitations upon the President’s use of military commis
sions, see post, at 682 (dissenting opinion), ignores the reasoning in Quirin.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
Cite as: 548 U. S. 557 (2006) 595
Opinion of Stevens, J.
itary commissions in circumstances where justified under the
“Constitution and laws,” including the law of war. Absent
a more specific congressional authorization, the task of this
Court is, as it was in Quirin, to decide whether Hamdan’s
military commission is so justified. It is to that inquiry we
now turn.
V
The common law governing military commissions may be
gleaned from past practice and what sparse legal precedent
exists. Commissions historically have been used in three
situations. See Bradley & Goldsmith, Congressional Au
thorization and the War on Terrorism, 118 Harv. L. Rev.
2048, 2132–2133 (2005); Winthrop 831–846; Hearings on H. R.
2498 before the Subcommittee of the House Committee on
Armed Services, 81st Cong., 1st Sess., 975 (1949). First,
they have substituted for civilian courts at times and in
places where martial law has been declared. Their use in
these circumstances has raised constitutional questions, see
Duncan v. Kahanamoku, 327 U. S. 304 (1946); Milligan, 4
Wall., at 121–122, but is well recognized.25 See Winthrop
822, 836–839. Second, commissions have been established
to try civilians “as part of a temporary military government
over occupied enemy territory or territory regained from an
25 The justification for, and limitations on, these commissions were sum
marized in Milligan:
“If, in foreign invasion or civil war, the courts are actually closed, and
it is impossible to administer criminal justice according to law, then, on
the theatre of active military operations, where war really prevails, there
is a necessity to furnish a substitute for the civil authority, thus over
thrown, to preserve the safety of the army and society; and as no power
is left but the military, it is allowed to govern by martial rule until the
laws can have their free course. As necessity creates the rule, so it limits
its duration; for, if this government is continued after the courts are rein
stated, it is a gross usurpation of power. Martial rule can never exist
where the courts are open, and in the proper and unobstructed exercise
of their jurisdiction. It is also confined to the locality of actual war.” 4
Wall., at 127 (emphasis in original).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
596 HAMDAN v. RUMSFELD
Opinion of Stevens, J.
enemy where civilian government cannot and does not func
tion.” Duncan, 327 U. S., at 314; see Milligan, 4 Wall., at
141–142 (Chase, C. J., concurring in judgment) (distinguish
ing “martial law proper” from “military government”
in occupied territory). Illustrative of this second kind of
commission is the one that was established, with jurisdiction
to apply the German Criminal Code, in occupied Germany
following the end of World War II. See Madsen v. Kinsella,
343 U. S. 341, 356 (1952).26
The third type of commission, convened as an “incident to
the conduct of war” when there is a need “to seize and sub
ject to disciplinary measures those enemies who in their at
tempt to thwart or impede our military effort have violated
the law of war,” Quirin, 317 U. S., at 28–29, has been de
scribed as “utterly different” from the other two. Bickers,
Military Commissions are Constitutionally Sound: A Re
sponse to Professors Katyal and Tribe, 34 Tex. Tech. L. Rev.
899, 902 (2002–2003).27 Not only is its jurisdiction limited to
offenses cognizable during time of war, but its role is primar
ily a factfinding one—to determine, typically on the battle
26 The limitations on these occupied territory or military government
commissions are tailored to the tribunals’ purpose and the exigencies that
necessitate their use. They may be employed “pending the establishment
of civil government,” Madsen, 343 U. S., at 354–355, which may in some
cases extend beyond the “cessation of hostilities,” id., at 348.
27 So much may not be evident on cold review of the Civil War trials
often cited as precedent for this kind of tribunal because the commissions
established during that conflict operated as both martial law or military
government tribunals and law-of-war commissions. Hence, “military
commanders began the practice [during the Civil War] of using the same
name, the same rules, and often, the same tribunals” to try both ordinary
crimes and war crimes. Bickers, 34 Tex. Tech. L. Rev., at 908. “For the
first time, accused horse thieves and alleged saboteurs found themselves
subject to trial by the same military commission.” Id., at 909. The Civil
War precedents must therefore be considered with caution; as we recog
nized in Quirin, 317 U. S., at 29, and as further discussed below, com
missions convened during time of war but under neither martial law nor
military government may try only offenses against the law of war.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
Cite as: 548 U. S. 557 (2006) 597
Opinion of Stevens, J.
field itself, whether the defendant has violated the law of
war. The last time the U. S. Armed Forces used the law-of
war military commission was during World War II. In
Quirin, this Court sanctioned President Roosevelt’s use of
such a tribunal to try Nazi saboteurs captured on American
soil during the War. 317 U. S. 1. And in Yamashita, we
held that a military commission had jurisdiction to try a Jap
anese commander for failing to prevent troops under his
command from committing atrocities in the Philippines. 327
U. S. 1.
Quirin is the model the Government invokes most fre
quently to defend the commission convened to try Hamdan.
That is both appropriate and unsurprising. Since Guantan
amo Bay is neither enemy-occupied territory nor under mar
tial law, the law-of-war commission is the only model avail
able. At the same time, no more robust model of executive
power exists; Quirin represents the high-water mark of mili
tary power to try enemy combatants for war crimes.
The classic treatise penned by Colonel William Winthrop,
whom we have called “the ‘Blackstone of Military Law,’ ”
Reid v. Covert, 354 U. S. 1, 19, n. 38 (1957) (plurality opinion),
describes at least four preconditions for exercise of jurisdic
tion by a tribunal of the type convened to try Hamdan.
First, “[a] military commission, (except where otherwise au
thorized by statute), can legally assume jurisdiction only of
offences committed within the field of the command of the
convening commander.” Winthrop 836. The “field of the
command” in these circumstances means the “theatre of
war.” Ibid. Second, the offense charged “must have been
committed within the period of the war.” 28 Id., at 837. No
jurisdiction exists to try offenses “committed either before
or after the war.” Ibid. Third, a military commission not
established pursuant to martial law or an occupation may try
28 If the commission is established pursuant to martial law or military
government, its jurisdiction extends to offenses committed within “the
exercise of military government or martial law.” Winthrop 837.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
598 HAMDAN v. RUMSFELD
Opinion of Stevens, J.
only “[i]ndividuals of the enemy’s army who have been guilty
of illegitimate warfare or other offences in violation of the
laws of war” and members of one’s own army “who, in time
of war, become chargeable with crimes or offences not cogni
zable, or triable, by the criminal courts or under the Articles
of war.” Id., at 838. Finally, a law-of-war commission has
jurisdiction to try only two kinds of offense: “Violations of
the laws and usages of war cognizable by military tribunals
only,” and “[b]reaches of military orders or regulations for
which offenders are not legally triable by court-martial
under the Articles of war.” Id., at 839.29
All parties agree that Colonel Winthrop’s treatise accu
rately describes the common law governing military commis
sions, and that the jurisdictional limitations he identifies
were incorporated in Article of War 15 and, later, Article 21
of the UCMJ. It also is undisputed that Hamdan’s commis
sion lacks jurisdiction to try him unless the charge “properly
set[s] forth, not only the details of the act charged, but the
circumstances conferring jurisdiction.” Id., at 842 (empha
sis in original). The question is whether the preconditions
designed to ensure that a military necessity exists to justify
the use of this extraordinary tribunal have been satisfied
here.
The charge against Hamdan, described in detail in Part I,
supra, alleges a conspiracy extending over a number of
years, from 1996 to November 2001.30 All but two months
of that more than 5-year-long period preceded the attacks of
29 Winthrop adds as a fifth, albeit not-always-complied-with, criterion
that “the trial must be had within the theatre of war . . . ; that, if held
elsewhere, and where the civil courts are open and available, the proceed
ings and sentence will be coram non judice.” Id., at 836. The Govern
ment does not assert that Guantanamo Bay is a theater of war, but instead
suggests that neither Washington, D. C., in 1942 nor the Philippines in
1945 qualified as a “war zone” either. Brief for Respondents 27;
cf. Quirin, 317 U. S. 1; In re Yamashita, 327 U. S. 1 (1946).
30 The elements of this conspiracy charge have been defined not by Con
gress but by the President. See Military Commission Instruction No. 2,
32 CFR § 11.6 (2005).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
599 Cite as: 548 U. S. 557 (2006)
Opinion of Stevens, J.
September 11, 2001, and the enactment of the AUMF—the
Act of Congress on which the Government relies for exercise
of its war powers and thus for its authority to convene mili
tary commissions.31 Neither the purported agreement with
31 Justice Thomas would treat Usama bin Laden’s 1996 declaration of
jihad against Americans as the inception of the war. See post, at 683–688
(dissenting opinion). But even the Government does not go so far; al
though the United States had for some time prior to the attacks of Sep
tember 11, 2001, been aggressively pursuing al Qaeda, neither in the
charging document nor in submissions before this Court has the Govern
ment asserted that the President’s war powers were activated prior to
September 11, 2001. Cf. Brief for Respondents 25 (describing the events
of September 11, 2001, as “an act of war” that “triggered a right to deploy
military forces abroad to defend the United States by combating al
Qaeda”). Justice Thomas’ further argument that the AUMF is “back
ward looking” and therefore authorizes trial by military commission of
crimes that occurred prior to the inception of war is insupportable. See
post, at 685, n. 3. If nothing else, Article 21 of the UCMJ requires that
the President comply with the law of war in his use of military commis
sions. As explained in the text, the law of war permits trial only of of
fenses “committed within the period of the war.” Winthrop 837; see also
Quirin, 317 U. S., at 28–29 (observing that law-of-war military commis
sions may be used to try “those enemies who in their attempt to thwart
or impede our military effort have violated the law of war” (emphasis
added)). The sources that Justice Thomas relies on to suggest other
wise simply do not support his position. Colonel Green’s short exegesis
on military commissions cites Howland for the proposition that “[o]ffenses
committed before a formal declaration of war or before the declaration
of martial law may be tried by military commission.” The Military Com
mission, 42 Am. J. Int’l L. 832, 848 (1948) (emphasis added) (cited post, at
686). Assuming that to be true, nothing in our analysis turns on the ad
mitted absence of either a formal declaration of war or a declaration of
martial law. Our focus instead is on the September 11, 2001, attacks that
the Government characterizes as the relevant “act[s] of war,” and on the
measure that authorized the President’s deployment of military force—
the AUMF. Because we do not question the Government’s position that
the war commenced with the events of September 11, 2001, the Prize
Cases, 2 Black 635 (1863) (cited post, at 679, 684, 685, and 687 (Thomas, J.,
dissenting)), are not germane to the analysis.
Finally, Justice Thomas’ assertion that Julius Otto Kuehn’s trial by
military commission “for conspiring with Japanese officials to betray the
United States Fleet to the Imperial Japanese Government prior to its

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
600 HAMDAN v. RUMSFELD
Opinion of Stevens, J.
Usama bin Laden and others to commit war crimes, nor a
single overt act, is alleged to have occurred in a theater of
war or on any specified date after September 11, 2001.
None of the overt acts that Hamdan is alleged to have com
mitted violates the law of war.
These facts alone cast doubt on the legality of the charge
and, hence, the commission; as Winthrop makes plain, the
offense alleged must have been committed both in a theater
of war and during, not before, the relevant conflict. But the
deficiencies in the time and place allegations also under
score—indeed are symptomatic of—the most serious defect
of this charge: The offense it alleges is not triable by law-of
war military commission. See Yamashita, 327 U. S., at 13
(“Neither congressional action nor the military orders consti
tuting the commission authorized it to place petitioner on
trial unless the charge proffered against him is of a violation
of the law of war”).32
attack on Pearl Harbor” stands as authoritative precedent for Hamdan’s
trial by commission, post, at 686, misses the mark in three critical respects.
First, Kuehn was tried for federal espionage crimes under what were then
50 U. S. C. §§ 31, 32, and 34, not with common-law violations of the law of
war. See Hearings before the Joint Committee on the Investigation of
the Pearl Harbor Attack, 79th Cong., 1st Sess., pt. 30, pp. 3067–3069 (1946).
Second, he was tried by martial law commission (a kind of commission
Justice Thomas acknowledges is not relevant to the analysis here, and
whose jurisdiction extends to offenses committed within “the exercise of
. . . martial law,” Winthrop 837; see, n. 28, supra), not a commission estab
lished exclusively to try violations of the law of war, see Winthrop 837.
Third, the martial law commissions established to try crimes in Hawaii
were ultimately declared illegal by this Court. See Duncan v. Kahana
moku, 327 U. S. 304, 324 (1946) (“The phrase ‘martial law’ as employed in
[the Hawaiian Organic Act], while intended to authorize the military to
act vigorously for the maintenance of an orderly civil government and for
the defense of the Islands against actual or threatened rebellion or inva
sion, was not intended to authorize the supplanting of courts by military
tribunals”).
32 Justice Thomas adopts the remarkable view, not advocated by the
Government, that the charging document in this case actually includes
more than one charge: Conspiracy and several other ill-defined crimes,

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
601 Cite as: 548 U. S. 557 (2006)
Opinion of Stevens, J.
There is no suggestion that Congress has, in exercise of
its constitutional authority to “define and punish . . . Offences
against the Law of Nations,” U. S. Const., Art. I, § 8, cl. 10,
like “joining an organization” that has a criminal purpose, “ ‘[b]eing a guer
rilla,’ ” and aiding the enemy. See post, at 693–697, and n. 9. There are
innumerable problems with this approach.
First, the crimes Justice Thomas identifies were not actually charged.
It is one thing to observe that charges before a military commission “ ‘need
not be stated with the precision of a common law indictment,’ ” post, at
692, n. 7; it is quite another to say that a crime not charged may nonethe
less be read into an indictment. Second, the Government plainly had
available to it the tools and the time it needed to charge petitioner with
the various crimes Justice Thomas refers to, if it believed they were
supported by the allegations. As Justice Thomas himself observes, see
post, at 697, the crime of aiding the enemy may, in circumstances where
the accused owes allegiance to the party whose enemy he is alleged to
have aided, be triable by military commission pursuant to Article 104 of
the UCMJ, 10 U. S. C. § 904. Indeed, the Government has charged detain
ees under this provision when it has seen fit to do so. See Brief for David
Hicks as Amicus Curiae 7.
Third, the cases Justice Thomas relies on to show that Hamdan may
be guilty of violations of the law of war not actually charged do not sup
port his argument. Justice Thomas begins by blurring the distinction
between those categories of “offender” who may be tried by military com
mission (e. g., jayhawkers and the like) with the “offenses” that may be so
tried. Even when it comes to “ ‘being a guerrilla,’ ” cf. post, at 695, n. 9,
a label alone does not render a person susceptible to execution or other
criminal punishment; the charge of “ ‘being a guerrilla’ ” invariably is ac
companied by the allegation that the defendant “ ‘took up arms’ ” as such.
This is because, as explained by Judge Advocate General Holt in a decision
upholding the charge of “ ‘being a guerrilla’ ” as one recognized by “the
universal usage of the times,” the charge is simply shorthand (akin to
“being a spy”) for “the perpetration of a succession of similar acts” of
violence. Record Books of the Judge Advocate General Office, R. 3, 590.
The sources cited by Justice Thomas confirm as much. See cases cited
post, at 694–695, n. 9.
Likewise, the suggestion that the Nuremberg precedents support Ham
dan’s conviction for the (uncharged) crime of joining a criminal organiza
tion must fail. Cf. post, at 695–697. The convictions of certain high-level
Nazi officials for “membership in a criminal organization” were secured
pursuant to specific provisions of the Charter of the International Military

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
602 HAMDAN v. RUMSFELD
Opinion of Stevens, J.
positively identified “conspiracy” as a war crime.33 As we
explained in Quirin, that is not necessarily fatal to the Gov
ernment’s claim of authority to try the alleged offense by
military commission; Congress, through Article 21 of the
UCMJ, has “incorporated by reference” the common law of
war, which may render triable by military commission cer
tain offenses not defined by statute. 317 U. S., at 30.
When, however, neither the elements of the offense nor the
range of permissible punishments is defined by statute or
treaty, the precedent must be plain and unambiguous. To
demand any less would be to risk concentrating in military
hands a degree of adjudicative and punitive power in excess
of that contemplated either by statute or by the Constitution.
Cf. Loving v. United States, 517 U. S. 748, 771 (1996) (ac
knowledging that Congress “may not delegate the power to
make laws”); Reid, 354 U. S., at 23–24 (“The Founders envi
sioned the army as a necessary institution, but one danger
ous to liberty if not confined within its essential bounds”);
The Federalist No. 47, p. 324 (J. Cooke ed. 1961) (J. Madison)
(“The accumulation of all powers legislative, executive and
judiciary in the same hands . . . may justly be pronounced
the very definition of tyranny”).34
Tribunal that permitted indictment of individual organization members
following convictions of the organizations themselves. See Arts. 9 and
10, in 1 Trial of the Major War Criminals Before the International Military
Tribunal: Nuremberg, 14 November 1945–1 October 1946, p. 12 (1947).
The initial plan to use organizations’ convictions as predicates for mass
individual trials ultimately was abandoned. See T. Taylor, Anatomy of
the Nuremberg Trials: A Personal Memoir 584–585, 638 (1992).
33 Cf. 10 U. S. C. § 904 (making triable by military commission the crime
of aiding the enemy); § 906 (same for spying); War Crimes Act of 1996,
18 U. S. C. § 2441 (2000 ed. and Supp. III) (listing war crimes); Foreign
Operations, Export Financing, and Related Programs Appropriations Act,
1998, § 583, 111 Stat. 2436 (same).
34 While the common law necessarily is “evolutionary in nature,” post,
at 689 (Thomas, J., dissenting), even in jurisdictions where common-law
crimes are still part of the penal framework, an act does not become a

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
603 Cite as: 548 U. S. 557 (2006)
Opinion of Stevens, J.
This high standard was met in Quirin; the violation there
alleged was, by “universal agreement and practice” both in
this country and internationally, recognized as an offense
against the law of war. 317 U. S., at 30; see id., at 35–36
(“This precept of the law of war has been so recognized in
practice both here and abroad, and has so generally been
accepted as valid by authorities on international law that we
think it must be regarded as a rule or principle of the law of
war recognized by this Government by its enactment of the
Fifteenth Article of War” (footnote omitted)). Although the
picture arguably was less clear in Yamashita, compare 327
U. S., at 16 (stating that the provisions of the Fourth Hague
Convention of 1907, 36 Stat. 2306, “plainly” required the de
fendant to control the troops under his command), with 327
U. S., at 35 (Murphy, J., dissenting), the disagreement be
tween the majority and the dissenters in that case concerned
whether the historic and textual evidence constituted clear
precedent—not whether clear precedent was required to jus
tify trial by law-of-war military commission.
At a minimum, the Government must make a substantial
showing that the crime for which it seeks to try a defendant
by military commission is acknowledged to be an offense
against the law of war. That burden is far from satisfied
here. The crime of “conspiracy” has rarely if ever been
tried as such in this country by any law-of-war military com
crime without its foundations having been firmly established in precedent.
See, e. g., Queen v. Rimmington, [2006] 2 All E. R. 257, 275–279 (2005)
(House of Lords); id., at 279 (while “some degree of vagueness is inevitable
and development of the law is a recognised feature of common law
courts[,] . . . the law-making function of the courts must remain within
reasonable limits”); see also Rogers v. Tennessee, 532 U. S. 451, 472–478
(2001) (Scalia, J., dissenting). The caution that must be exercised in the
incremental development of common-law crimes by the judiciary is, for
the reasons explained in the text, all the more critical when reviewing
developments that stem from military action.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
604 HAMDAN v. RUMSFELD
Opinion of Stevens, J.
mission not exercising some other form of jurisdiction,35 and
does not appear in either the Geneva Conventions or the
Hague Conventions—the major treaties on the law of war.36
Winthrop explains that under the common law governing
military commissions, it is not enough to intend to violate
the law of war and commit overt acts in furtherance of that
intention unless the overt acts either are themselves offenses
against the law of war or constitute steps sufficiently sub
stantial to qualify as an attempt. See Winthrop 841 (“[T]he
jurisdiction of the military commission should be restricted
to cases of offence consisting in overt acts, i. e. in unlawful
commissions or actual attempts to commit, and not in inten
tions merely” (emphasis in original)).
The Government cites three sources that it says show oth
erwise. First, it points out that the Nazi saboteurs in
Quirin were charged with conspiracy. See Brief for Re
spondents 27. Second, it observes that Winthrop at one
35 The 19th-century trial of the “Lincoln conspirators,” even if properly
classified as a trial by law-of-war commission, cf. W. Rehnquist, All the
Laws But One: Civil Liberties in Wartime 165–167 (1998) (analyzing the
conspiracy charges in light of ordinary criminal law principles at the time),
is at best an equivocal exception. Although the charge against the de
fendants in that case accused them of “combining, confederating, and con
spiring together” to murder the President, they were also charged (as we
read the indictment, cf. post, at 699–700, n. 12 (Thomas, J., dissenting)),
with “maliciously, unlawfully, and traitorously murdering the said Abra
ham Lincoln.” H. R. Doc. No. 314, 55th Cong., 3d Sess., 696 (1899).
Moreover, the Attorney General who wrote the opinion defending the trial
by military commission treated the charge as if it alleged the substantive
offense of assassination. See 11 Op. Atty. Gen. 297 (1865) (analyzing the
propriety of trying by military commission “the offence of having assassi
nated the President”); see also Mudd v. Caldera, 134 F. Supp. 2d 138, 140
(DC 2001).
36 By contrast, the Geneva Conventions do extend liability for substan
tive war crimes to those who “orde[r]” their commission, see Third Geneva
Convention, Art. 129, 6 U. S. T., at 3418, and this Court has read the
Fourth Hague Convention of 1907 to impose “command responsibility” on
military commanders for acts of their subordinates, see Yamashita, 327
U. S., at 15–16.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
605 Cite as: 548 U. S. 557 (2006)
Opinion of Stevens, J.
point in his treatise identifies conspiracy as an offense “pros
ecuted by military commissions.” Ibid. (citing Winthrop
839, and n. 5). Finally, it notes that another military histo
rian, Charles Roscoe Howland, lists conspiracy “ ‘to violate
the laws of war by destroying life or property in aid of the
enemy’ ” as an offense that was tried as a violation of the law
of war during the Civil War. Brief for Respondents 27–28
(citing C. Howland, Digest of Opinions of the Judge Advo
cates General of the Army 1071 (1912) (hereinafter How
land)). On close analysis, however, these sources at best
lend little support to the Government’s position and at worst
undermine it. By any measure, they fail to satisfy the high
standard of clarity required to justify the use of a military
commission.
That the defendants in Quirin were charged with conspir
acy is not persuasive, since the Court declined to address
whether the offense actually qualified as a violation of the
law of war—let alone one triable by military commission.
The Quirin defendants were charged with the following
offenses:
“[I.] Violation of the law of war.
“[II.] Violation of Article 81 of the Articles of War, de
fining the offense of relieving or attempting to relieve,
or corresponding with or giving intelligence to, the
enemy.
“[III.] Violation of Article 82, defining the offense of
spying.
“[IV.] Conspiracy to commit the offenses alleged in
charges [I, II, and III].” 317 U. S., at 23.
The Government, defending its charge, argued that the con
spiracy alleged “constitute[d] an additional violation of the
law of war.” Id., at 15. The saboteurs disagreed; they
maintained that “[t]he charge of conspiracy can not stand if
the other charges fall.” Id., at 8. The Court, however, de
clined to resolve the dispute. It concluded, first, that the

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
606 HAMDAN v. RUMSFELD
Opinion of Stevens, J.
specification supporting Charge I adequately alleged a “vio
lation of the law of war” that was not “merely colorable
or without foundation.” Id., at 36. The facts the Court
deemed sufficient for this purpose were that the defendants,
admitted enemy combatants, entered upon U. S. territory in
time of war without uniform “for the purpose of destroying
property used or useful in prosecuting the war.” That act
was “a hostile and warlike” one. Id., at 36, 37. The Court
was careful in its decision to identify an overt, “complete”
act. Responding to the argument that the saboteurs had
“not actually committed or attempted to commit any act of
depredation or entered the theatre or zone of active military
operations” and therefore had not violated the law of war,
the Court responded that they had actually “passed our mili
tary and naval lines and defenses or went behind those lines,
in civilian dress and with hostile purpose.” Id., at 38. “The
offense was complete when with that purpose they entered—
or, having so entered, they remained upon—our territory in
time of war without uniform or other appropriate means of
identification.” Ibid.
Turning to the other charges alleged, the Court explained
that “[s]ince the first specification of Charge I sets forth a
violation of the law of war, we have no occasion to pass on
the adequacy of the second specification of Charge I, or to
construe the 81st and 82nd Articles of War for the purpose
of ascertaining whether the specifications under Charges II
and III allege violations of those Articles or whether if so
construed they are constitutional.” Id., at 46. No mention
was made at all of Charge IV—the conspiracy charge.
If anything, Quirin supports Hamdan’s argument that con
spiracy is not a violation of the law of war. Not only did the
Court pointedly omit any discussion of the conspiracy charge,
but its analysis of Charge I placed special emphasis on the
completion of an offense; it took seriously the saboteurs’ ar
gument that there can be no violation of a law of war—at
least not one triable by military commission—without the

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
607 Cite as: 548 U. S. 557 (2006)
Opinion of Stevens, J.
actual commission of or attempt to commit a “hostile and
warlike act.” Id., at 37–38.
That limitation makes eminent sense when one considers
the necessity from whence this kind of military commission
grew: The need to dispense swift justice, often in the form of
execution, to illegal belligerents captured on the battlefield.
See S. Rep. No. 130, 64th Cong., 1st Sess., 40 (1916) (tes
timony of Brig. Gen. Enoch H. Crowder) (observing that
Article of War 15 preserves the power of “the military
commander in the field in time of war” to use military
commissions (emphasis added)). The same urgency would
not have been felt vis-a` -vis enemies who had done little more
than agree to violate the laws of war. Cf. 31 Op. Atty. Gen.
356, 357, 361 (1918) (opining that a German spy could not be
tried by military commission because, having been appre
hended before entering “any camp, fortification or other mili
tary premises of the United States,” he had “committed [his
offenses] outside of the field of military operations”). The
Quirin Court acknowledged as much when it described the
President’s authority to use law-of-war military commissions
as the power to “seize and subject to disciplinary measures
those enemies who in their attempt to thwart or impede our
military effort have violated the law of war.” 317 U. S., at
28–29 (emphasis added).
Winthrop and Howland are only superficially more helpful
to the Government. Howland, granted, lists “conspiracy by
two or more to violate the laws of war by destroying life or
property in aid of the enemy” as one of over 20 “offenses
against the laws and usages of war” “passed upon and pun
ished by military commissions.” Howland 1070–1071. But
while the records of cases that Howland cites following his
list of offenses against the law of war support inclusion of
the other offenses mentioned, they provide no support for
the inclusion of conspiracy as a violation of the law of war.
See id., at 1071 (citing Record Books of the Judge Advocate
General Office, R. 2, 144; R. 3, 401, 589, 649; R. 4, 320; R. 5,

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
608 HAMDAN v. RUMSFELD
Opinion of Stevens, J.
36, 590; R. 6, 20; R. 7, 413; R. 8, 529; R. 9, 149, 202, 225, 481,
524, 535; R. 10, 567; R. 11, 473, 513; R. 13, 125, 675; R. 16,
446; R. 21, 101, 280). Winthrop, apparently recognizing as
much, excludes conspiracy of any kind from his own list of
offenses against the law of war. See Winthrop 839–840.
Winthrop does, unsurprisingly, include “criminal conspira
cies” in his list of “[c]rimes and statutory offenses cognizable
by State or U. S. courts” and triable by martial law or mili
tary government commission. See id., at 839. And, in a
footnote, he cites several Civil War examples of “conspiracies
of this class, or of the first and second classes combined.”
Id., at 839, n. 5 (emphasis added). The Government relies
on this footnote for its contention that conspiracy was triable
both as an ordinary crime (a crime of the “first class”) and,
independently, as a war crime (a crime of the “second class”).
But the footnote will not support the weight the Government
places on it.
As we have seen, the military commissions convened dur
ing the Civil War functioned at once as martial law or mili
tary government tribunals and as law-of-war commissions.
See n. 27, supra. Accordingly, they regularly tried war
crimes and ordinary crimes together. Indeed, as Howland
observes, “[n]ot unfrequently the crime, as charged and
found, was a combination of the two species of offenses.”
Howland 1071; see also Davis 310, n. 2; Winthrop 842. The
example he gives is “ ‘murder in violation of the laws of
war.’ ” Howland 1071–1072. Winthrop’s conspiracy “of the
first and second classes combined” is, like Howland’s exam
ple, best understood as a species of compound offense of the
type tried by the hybrid military commissions of the Civil
War. It is not a stand-alone offense against the law of war.
Winthrop confirms this understanding later in his discussion,
when he emphasizes that “overt acts” constituting war
crimes are the only proper subject at least of those military
tribunals not convened to stand in for local courts. Win
throp 841, and nn. 22, 23 (citing W. Finlason, Martial Law
130 (1867); emphasis in original).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
609 Cite as: 548 U. S. 557 (2006)
Opinion of Stevens, J.
Justice Thomas cites as evidence that conspiracy is a rec
ognized violation of the law of war the Civil War indictment
against Henry Wirz, which charged the defendant with
“ ‘[m]aliciously, willfully, and traitorously . . . combining, con
federating, and conspiring [with others] to injure the health
and destroy the lives of soldiers in the military service of the
United States . . . to the end that the armies of the United
States might be weakened and impaired, in violation of the
laws and customs of war.’ ” Post, at 701 (dissenting opin
ion) (quoting H. R. Doc. No. 314, 55th Cong., 3d Sess., 785
(1899); emphasis deleted). As shown by the specification
supporting that charge, however, Wirz was alleged to have
personally committed a number of atrocities against his vic
tims, including torture, injection of prisoners with poison,
and use of “ferocious and bloodthirsty dogs” to “seize, tear,
mangle, and maim the bodies and limbs” of prisoners, many
of whom died as a result. Id., at 789–790. Crucially, Judge
Advocate General Holt determined that one of Wirz’s alleged
co-conspirators, R. B. Winder, should not be tried by military
commission because there was as yet insufficient evidence of
his own personal involvement in the atrocities: “[I]n the case
of R. B. Winder, while the evidence at the trial of Wirz was
deemed by the court to implicate him in the conspiracy
against the lives of all Federal prisoners in rebel hands, no
such specific overt acts of violation of the laws of war are
as yet fixed upon him as to make it expedient to prefer for
mal charges and bring him to trial.” Id., at 783 (emphasis
added).37
37 The other examples Justice Thomas offers are no more availing.
The Civil War indictment against Robert Louden, cited post, at 702, al
leged a conspiracy, but not one in violation of the law of war. See War
Dept., General Court Martial Order No. 41, p. 20 (1864). A separate
charge of “ ‘[t]ransgression of the laws and customs of war’ ” made no men
tion of conspiracy. Id., at 17. The charge against Leger Grenfel and oth
ers for conspiring to release rebel prisoners held in Chicago only supports
the observation, made in the text, that the Civil War tribunals often
charged hybrid crimes mixing elements of crimes ordinarily triable in ci
vilian courts (like treason) and violations of the law of war. Judge Advo

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
610 HAMDAN v. RUMSFELD
Opinion of Stevens, J.
Finally, international sources confirm that the crime
charged here is not a recognized violation of the law of war.38
As observed above, see supra, at 603–604, none of the major
treaties governing the law of war identifies conspiracy as a
violation thereof. And the only “conspiracy” crimes that
have been recognized by international war crimes tribunals
(whose jurisdiction often extends beyond war crimes proper
to crimes against humanity and crimes against the peace)
are conspiracy to commit genocide and common plan to wage
aggressive war, which is a crime against the peace and re
quires for its commission actual participation in a “concrete
plan to wage war.” 1 Trial of the Major War Criminals
Before the International Military Tribunal: Nuremberg, 14
November 1945–1 October 1946, p. 225 (1947) (hereinafter
Trial of Major War Criminals). The International Military
Tribunal at Nuremberg, over the prosecution’s objections,
pointedly refused to recognize as a violation of the law of
war conspiracy to commit war crimes, see, e. g., 22 id., at
469,39 and convicted only Hitler’s most senior associates of
conspiracy to wage aggressive war, see S. Pomorski, Con
cate General Holt, in recommending that Grenfel’s death sentence be up
held (it was in fact commuted by Presidential decree, see H. R. Doc.
No. 314, at 725), explained that the accused “united himself with traitors
and malefactors for the overthrow of our Republic in the interest of slav
ery.” Id., at 689.
38 The Court in Quirin “assume[d] that there are acts regarded in other
countries, or by some writers on international law, as offenses against the
law of war which would not be triable by military tribunal here, either
because they are not recognized by our courts as violations of the law of
war or because they are of that class of offenses constitutionally triable
only by a jury.” 317 U. S., at 29. We need not test the validity of that
assumption here because the international sources only corroborate the
domestic ones.
39 Accordingly, the Tribunal determined to “disregard the charges . . .
that the defendants conspired to commit War Crimes and Crimes against
Humanity.” 22 Trial of Major War Criminals 469; see also ibid. (“[T]he
Charter does not define as a separate crime any conspiracy except the one
to commit acts of aggressive war”).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
611 Cite as: 548 U. S. 557 (2006)
Opinion of Stevens, J.
spiracy and Criminal Organization, in the Nuremberg Trial
and International Law 213, 233–235 (G. Ginsburgs & V.
Kudriavtsev eds. 1990). As one prominent figure from the
Nuremberg trials has explained, members of the Tribunal
objected to recognition of conspiracy as a violation of the law
of war on the ground that “[t]he Anglo-American concept of
conspiracy was not part of European legal systems and argu
ably not an element of the internationally recognized laws
of war.” T. Taylor, Anatomy of the Nuremberg Trials: A
Personal Memoir 36 (1992); see also id., at 550 (observing
that Francis Biddle, who as Attorney General prosecuted the
defendants in Quirin, thought the French judge had made a
“ ‘persuasive argument that conspiracy in the truest sense is
not known to international law’ ”).40
In sum, the sources that the Government and Justice
Thomas rely upon to show that conspiracy to violate the law
of war is itself a violation of the law of war in fact demon
strate quite the opposite. Far from making the requisite
substantial showing, the Government has failed even to offer
a “merely colorable” case for inclusion of conspiracy among
those offenses cognizable by law-of-war military commission.
Cf. Quirin, 317 U. S., at 36. Because the charge does not
40 See also 15 United Nations War Crimes Commissions, Law Reports
of Trials of War Criminals 90–91 (1949) (observing that, although a few
individuals were charged with conspiracy under European domestic crimi
nal codes following World War II, “the United States Military Tribunals”
established at that time did not “recognis[e] as a separate offence conspir
acy to commit war crimes or crimes against humanity”). The Interna
tional Criminal Tribunal for the former Yugoslavia (ICTY), drawing on
the Nuremberg precedents, has adopted a “joint criminal enterprise” the
ory of liability, but that is a species of liability for the substantive offense
(akin to aiding and abetting), not a crime on its own. See Prosecutor v.
Tadic´, Judgment, Case No. IT–94–1–A (ICTY App. Chamber, July 15,
1999); see also Prosecutor v. Milutinovic´, Decision on Dragoljub Ojdanic´ ’s
Motion Challenging Jurisdiction— Joint Criminal Enterprise, Case
No. IT–99–37–AR72, ¶ 26 (ICTY App. Chamber, May 21, 2003) (stating
that “[c]riminal liability pursuant to a joint criminal enterprise is not a
liability for . . . conspiring to commit crimes”).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
612 HAMDAN v. RUMSFELD
Opinion of Stevens, J.
support the commission’s jurisdiction, the commission lacks
authority to try Hamdan.
The charge’s shortcomings are not merely formal, but are
indicative of a broader inability on the Executive’s part here
to satisfy the most basic precondition—at least in the ab
sence of specific congressional authorization—for establish
ment of military commissions: military necessity. Hamdan’s
tribunal was appointed not by a military commander in the
field of battle, but by a retired major general stationed away
from any active hostilities. Cf. Rasul v. Bush, 542 U. S., at
487 (Kennedy, J., concurring in judgment) (observing that
“Guantanamo Bay is . . . far removed from any hostilities”).
Hamdan is charged not with an overt act for which he was
caught redhanded in a theater of war and which military
efficiency demands be tried expeditiously, but with an agree
ment the inception of which long predated the attacks of
September 11, 2001, and the AUMF. That may well be a
crime,41 but it is not an offense that “by the law of war may
be tried by military commissio[n].” 10 U. S. C. § 821. None
of the overt acts alleged to have been committed in further
ance of the agreement is itself a war crime, or even necessar
ily occurred during time of, or in a theater of, war. Any
urgent need for imposition or execution of judgment is ut
terly belied by the record; Hamdan was arrested in Novem
ber 2001 and he was not charged until mid-2004. These sim
ply are not the circumstances in which, by any stretch of
the historical evidence or this Court’s precedents, a military
commission established by Executive Order under the au
41 Justice Thomas’ suggestion that our conclusion precludes the Gov
ernment from bringing to justice those who conspire to commit acts of
terrorism is therefore wide of the mark. See post, at 686, n. 3, 704–706.
That conspiracy is not a violation of the law of war triable by military
commission does not mean the Government may not, for example, prose
cute by court-martial or in federal court those caught “plotting terrorist
atrocities like the bombing of the Khobar Towers.” Post, at 705.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
613 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
thority of Article 21 of the UCMJ may lawfully try a person
and subject him to punishment.
VI
Whether or not the Government has charged Hamdan with
an offense against the law of war cognizable by military com
mission, the commission lacks power to proceed. The
UCMJ conditions the President’s use of military commissions
on compliance not only with the American common law of
war, but also with the rest of the UCMJ itself, insofar as
applicable, and with the “rules and precepts of the law of
nations,” Quirin, 317 U. S., at 28—including, inter alia, the
four Geneva Conventions signed in 1949. See Yamashita,
327 U. S., at 20–21, 23–24. The procedures that the Govern
ment has decreed will govern Hamdan’s trial by commission
violate these laws.
A
The commission’s procedures are set forth in Commission
Order No. 1, which was amended most recently on August
31, 2005—after Hamdan’s trial had already begun. Every
commission established pursuant to Commission Order No. 1
must have a presiding officer and at least three other mem
bers, all of whom must be commissioned officers. § 4(A)(1).
The presiding officer’s job is to rule on questions of law and
other evidentiary and interlocutory issues; the other mem
bers make findings and, if applicable, sentencing decisions.
§ 4(A)(5). The accused is entitled to appointed military
counsel and may hire civilian counsel at his own expense so
long as such counsel is a U. S. citizen with security clearance
“at the level SECRET or higher.” §§ 4(C)(2)–(3).
The accused also is entitled to a copy of the charge(s)
against him, both in English and his own language (if differ
ent), to a presumption of innocence, and to certain other
rights typically afforded criminal defendants in civilian
courts and courts-martial. See §§ 5(A)–(P). These rights

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
614 HAMDAN v. RUMSFELD
Opinion of the Court
are subject, however, to one glaring condition: The accused
and his civilian counsel may be excluded from, and precluded
from ever learning what evidence was presented during, any
part of the proceeding that either the Appointing Authority
or the presiding officer decides to “close.” Grounds for such
closure “include the protection of information classified or
classifiable . . . ; information protected by law or rule from
unauthorized disclosure; the physical safety of participants
in Commission proceedings, including prospective witnesses;
intelligence and law enforcement sources, methods, or activi
ties; and other national security interests.” § 6(B)(3).42
Appointed military defense counsel must be privy to these
closed sessions, but may, at the presiding officer’s discretion,
be forbidden to reveal to his or her client what took place
therein. Ibid.
Another striking feature of the rules governing Hamdan’s
commission is that they permit the admission of any evi
dence that, in the opinion of the presiding officer, “would
have probative value to a reasonable person.” § 6(D)(1).
Under this test, not only is testimonial hearsay and evidence
obtained through coercion fully admissible, but neither live
testimony nor witnesses’ written statements need be sworn.
See §§ 6(D)(2)(b), (3). Moreover, the accused and his civilian
counsel may be denied access to evidence in the form of “pro
tected information” (which includes classified information as
well as “information protected by law or rule from unauthor
ized disclosure” and “information concerning other national
security interests,” §§ 6(B)(3), 6(D)(5)(a)(v)), so long as the
presiding officer concludes that the evidence is “probative”
under § 6(D)(1) and that its admission without the accused’s
knowledge would not “result in the denial of a full and fair
trial.” § 6(D)(5)(b).43 Finally, a presiding officer’s determi
42 The accused also may be excluded from the proceedings if he “engages
in disruptive conduct.” § 5(K).
43 As the District Court observed, this section apparently permits recep
tion of testimony from a confidential informant in circumstances where

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
Cite as: 548 U. S. 557 (2006) 615
Opinion of the Court
nation that evidence “would [not] have probative value to a
reasonable person” may be overridden by a majority of the
other commission members. § 6(D)(1).
Once all the evidence is in, the commission members (not
including the presiding officer) must vote on the accused’s
guilt. A two-thirds vote will suffice for both a verdict of
guilty and for imposition of any sentence not including death
(the imposition of which requires a unanimous vote). § 6(F).
Any appeal is taken to a three-member review panel com
posed of military officers and designated by the Secretary of
Defense, only one member of which need have experience as
a judge. § 6(H)(4). The review panel is directed to “dis
regard any variance from procedures specified in this Order
or elsewhere that would not materially have affected the out
come of the trial before the Commission.” Ibid. Once the
panel makes its recommendation to the Secretary of Defense,
the Secretary can either remand for further proceedings or
forward the record to the President with his recommen
dation as to final disposition. § 6(H)(5). The President
then, unless he has delegated the task to the Secretary,
makes the “final decision.” § 6(H)(6). He may change the
commission’s findings or sentence only in a manner favorable
to the accused. Ibid.
B
Hamdan raises both general and particular objections to
the procedures set forth in Commission Order No. 1. His
general objection is that the procedures’ admitted deviation
from those governing courts-martial itself renders the com
mission illegal. Chief among his particular objections are
that he may, under the Commission Order, be convicted
“Hamdan will not be permitted to hear the testimony, see the witness’s
face, or learn his name. If the government has information developed by
interrogation of witnesses in Afghanistan or elsewhere, it can offer such
evidence in transcript form, or even as summaries of transcripts.” 344
F. Supp. 2d 152, 168 (DC 2004).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
616 HAMDAN v. RUMSFELD
Opinion of the Court
based on evidence he has not seen or heard, and that any
evidence admitted against him need not comply with the ad
missibility or relevance rules typically applicable in criminal
trials and court-martial proceedings.
The Government objects to our consideration of any proce
dural challenge at this stage on the grounds that (1) the ab
stention doctrine espoused in Councilman, 420 U. S. 738,
precludes preenforcement review of procedural rules,
(2) Hamdan will be able to raise any such challenge following
a “final decision” under the DTA, and (3) “there is . . . no
basis to presume, before the trial has even commenced, that
the trial will not be conducted in good faith and according to
law.” Brief for Respondents 45–46, nn. 20–21. The first of
these contentions was disposed of in Part III, supra, and
neither of the latter two is sound.
First, because Hamdan apparently is not subject to the
death penalty (at least as matters now stand) and may
receive a sentence shorter than 10 years’ imprisonment, he
has no automatic right to review of the commission’s “final
decision” 44 before a federal court under the DTA. See
§ 1005(e)(3), 119 Stat. 2743. Second, contrary to the Govern
ment’s assertion, there is a “basis to presume” that the pro
cedures employed during Hamdan’s trial will violate the law:
The procedures are described with particularity in Commis
sion Order No. 1, and implementation of some of them has
already occurred. One of Hamdan’s complaints is that he
will be, and indeed already has been, excluded from his own
trial. See Reply Brief for Petitioner 12; App. to Pet. for
Cert. 45a. Under these circumstances, review of the proce
dures in advance of a “final decision”—the timing of which is
left entirely to the discretion of the President under the
DTA—is appropriate. We turn, then, to consider the merits
of Hamdan’s procedural challenge.
44 Any decision of the commission is not “final” until the President ren
ders it so. See Commission Order No. 1, § 6(H)(6).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
617 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
C
In part because the difference between military commis
sions and courts-martial originally was a difference of juris
diction alone, and in part to protect against abuse and ensure
evenhandedness under the pressures of war, the procedures
governing trials by military commission historically have
been the same as those governing courts-martial. See, e. g.,
1 The War of the Rebellion 248 (2d series 1894) (General
Order 1 issued during the Civil War required military com
missions to “be constituted in a similar manner and their
proceedings be conducted according to the same general
rules as courts-martial in order to prevent abuses which
might otherwise arise”). Accounts of commentators from
Winthrop through General Crowder—who drafted Article of
War 15 and whose views have been deemed “authoritative”
by this Court, Madsen, 343 U. S., at 353—confirm as much.45
As recently as the Korean and Vietnam wars, during which
use of military commissions was contemplated but never
made, the principle of procedural parity was espoused as a
background assumption. See Paust, Antiterrorism Military
Commissions: Courting Illegality, 23 Mich. J. Int’l L. 1, 3–5
(2001–2002).
There is a glaring historical exception to this general rule.
The procedures and evidentiary rules used to try General
Yamashita near the end of World War II deviated in signi
ficant respects from those then governing courts-martial.
45 See Winthrop 835, and n. 81 (“military commissions are constituted
and composed, and their proceedings are conducted, similarly to general
courts-martial”); id., at 841–842; S. Rep. No. 130, 64th Cong., 1st Sess., 40
(1916) (testimony of Gen. Crowder) (“Both classes of courts have the same
procedure”); see also, e. g., H. Coppe´ e, Field Manual of Courts-Martial 105
(1863) (“[Military] commissions are appointed by the same authorities as
those which may order courts-martial. They are constituted in a manner
similar to such courts, and their proceedings are conducted in exactly the
same way, as to form, examination of witnesses, etc.”).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
618 HAMDAN v. RUMSFELD
Opinion of the Court
See 327 U. S. 1. The force of that precedent, however,
has been seriously undermined by post-World War II
developments.
Yamashita, from late 1944 until September 1945, was Com
manding General of the Fourteenth Army Group of the Im
perial Japanese Army, which had exercised control over the
Philippine Islands. On September 3, 1945, after American
forces regained control of the Philippines, Yamashita surren
dered. Three weeks later, he was charged with violations
of the law of war. A few weeks after that, he was arraigned
before a military commission convened in the Philippines.
He pleaded not guilty, and his trial lasted for two months.
On December 7, 1945, Yamashita was convicted and sen
tenced to hang. See id., at 5; id., at 31–34 (Murphy, J., dis
senting). This Court upheld the denial of his petition for a
writ of habeas corpus.
The procedures and rules of evidence employed during Ya
mashita’s trial departed so far from those used in courts
martial that they generated an unusually long and vociferous
critique from two Members of this Court. See id., at 41–81
(Rutledge, J., joined by Murphy, J., dissenting).46 Among
the dissenters’ primary concerns was that the commission
had free rein to consider all evidence “which in the commis
sion’s opinion ‘would be of assistance in proving or disprov
ing the charge,’ without any of the usual modes of authenti
cation.” Id., at 49 (opinion of Rutledge, J.).
46 The dissenters’ views are summarized in the following passage:
“It is outside our basic scheme to condemn men without giving reason
able opportunity for preparing defense; in capital or other serious crimes
to convict on ‘official documents . . . ; affidavits; . . . documents or transla
tions thereof; diaries . . . , photographs, motion picture films, and . . .
newspapers’ or on hearsay, once, twice or thrice removed, more particu
larly when the documentary evidence or some of it is prepared ex parte
by the prosecuting authority and includes not only opinion but conclusions
of guilt. Nor in such cases do we deny the rights of confrontation of
witnesses and cross-examination.” Yamashita, 327 U. S., at 44 (foot
notes omitted).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
619 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
The majority, however, did not pass on the merits of Ya
mashita’s procedural challenges because it concluded that his
status disentitled him to any protection under the Articles
of War (specifically, those set forth in Article 38, which would
become Article 36 of the UCMJ) or the Geneva Convention
of 1929, 47 Stat. 2021 (1929 Geneva Convention). The Court
explained that Yamashita was neither a “person made sub
ject to the Articles of War by Article 2” thereof, 327 U. S.,
at 20, nor a protected prisoner of war being tried for crimes
committed during his detention, id., at 21.
At least partially in response to subsequent criticism of
General Yamashita’s trial, the UCMJ’s codification of the Ar
ticles of War after World War II expanded the category of
persons subject thereto to include defendants in Yamashita’s
(and Hamdan’s) position,47 and the Third Geneva Convention
of 1949 extended prisoner-of-war protections to individuals
tried for crimes committed before their capture. See 3 Int’l
Comm. of Red Cross,48 Commentary: Geneva Convention
Relative to the Treatment of Prisoners of War 413 (J. Pictet
gen. ed. 1960) (hereinafter GCIII Commentary) (explaining
47 Article 2 of the UCMJ now reads:
“(a) The following persons are subject to [the UCMJ]:
. . . . .
“(9) Prisoners of war in custody of the armed forces.
. . . . .
“(12) Subject to any treaty or agreement to which the United States is
or may be a party or to any accepted rule of international law, persons
within an area leased by or otherwise reserved or acquired for the use of
the United States which is under the control of the Secretary concerned
and which is outside the United States and outside the Commonwealth of
Puerto Rico, Guam, and the Virgin Islands.” 10 U. S. C. § 802(a).
Guantanamo Bay is such a leased area. See Rasul v. Bush, 542 U. S.
466, 471 (2004).
48 The International Committee of the Red Cross is referred to by name
in several provisions of the 1949 Geneva Conventions and is the body that
drafted and published the official commentary to the Conventions.
Though not binding law, the commentary is, as the parties recognize, rele
vant in interpreting the Conventions’ provisions.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
620 HAMDAN v. RUMSFELD
Opinion of the Court
that Article 85, which extends the Convention’s protections
to “[p]risoners of war prosecuted under the laws of the De
taining Power for acts committed prior to capture,” was
adopted in response to judicial interpretations of the 1929
Geneva Convention, including this Court’s decision in Ya
mashita). The most notorious exception to the principle of
uniformity, then, has been stripped of its precedential value.
The uniformity principle is not an inflexible one; it does
not preclude all departures from the procedures dictated for
use by courts-martial. But any departure must be tailored
to the exigency that necessitates it. See Winthrop 835,
n. 81. That understanding is reflected in Article 36 of the
UCMJ, which provides:
“(a) The procedure, including modes of proof, in cases
before courts-martial, courts of inquiry, military com
missions, and other military tribunals may be prescribed
by the President by regulations which shall, so far as he
considers practicable, apply the principles of law and the
rules of evidence generally recognized in the trial of
criminal cases in the United States district courts, but
which may not be contrary to or inconsistent with this
chapter.
“(b) All rules and regulations made under this article
shall be uniform insofar as practicable and shall be re
ported to Congress.” 70A Stat. 50.
Article 36 places two restrictions on the President’s power
to promulgate rules of procedure for courts-martial and mili
tary commissions alike. First, no procedural rule he adopts
may be “contrary to or inconsistent with” the UCMJ—how
ever practical it may seem. Second, the rules adopted must
be “uniform insofar as practicable.” That is, the rules ap
plied to military commissions must be the same as those
applied to courts-martial unless such uniformity proves
impracticable.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
Cite as: 548 U. S. 557 (2006) 621
Opinion of the Court
Hamdan argues that Commission Order No. 1 violates both
of these restrictions; he maintains that the procedures de
scribed in the Commission Order are inconsistent with the
UCMJ and that the Government has offered no explanation
for their deviation from the procedures governing courts
martial, which are set forth in the Manual for Courts-
Martial, United States (2005 ed.) (Manual for Courts-
Martial). Among the inconsistencies Hamdan identifies is
that between § 6 of the Commission Order, which permits
exclusion of the accused from proceedings and denial of his
access to evidence in certain circumstances, and the UCMJ’s
requirement that “[a]ll . . . proceedings” other than votes and
deliberations by courts-martial “shall be made a part of the
record and shall be in the presence of the accused.” 10
U. S. C. § 839(c) (2000 ed., Supp. V). Hamdan also observes
that the Commission Order dispenses with virtually all evi
dentiary rules applicable in courts-martial.
The Government has three responses. First, it argues,
only 9 of the UCMJ’s 158 Articles—the ones that expressly
mention “military commissions” 49—actually apply to com
missions, and Commission Order No. 1 sets forth no pro
49 Aside from Articles 21 and 36, discussed at length in the text, the
other seven Articles that expressly reference military commissions are:
(1) 28 (requiring appointment of reporters and interpreters); (2) 47 (mak
ing it a crime to refuse to appear or testify “before a court-martial, mili
tary commission, court of inquiry, or any other military court or board”);
(3) 48 (allowing a “court-martial, provost court, or military commission”
to punish a person for contempt); (4) 49(d) (permitting admission into evi
dence of a “duly authenticated deposition taken upon reasonable notice to
the other parties” only if “admissible under the rules of evidence” and
only if the witness is otherwise unavailable); (5) 50 (permitting admission
into evidence of records of courts of inquiry “if otherwise admissible under
the rules of evidence,” and if certain other requirements are met); (6) 104
(providing that a person accused of aiding the enemy may be sentenced to
death or other punishment by military commission or court-martial); and
(7) 106 (mandating the death penalty for spies convicted before military
commission or court-martial).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
622 HAMDAN v. RUMSFELD
Opinion of the Court
cedure that is “contrary to or inconsistent with” those 9
provisions. Second, the Government contends, military
commissions would be of no use if the President were ham
strung by those provisions of the UCMJ that govern courts
martial. Finally, the President’s determination that “the
danger to the safety of the United States and the nature of
international terrorism” renders it impracticable “to apply
in military commissions . . . the principles of law and the
rules of evidence generally recognized in the trial of criminal
cases in the United States district courts,” November 13
Order § 1(f), is, in the Government’s view, explanation
enough for any deviation from court-martial procedures.
See Brief for Respondents 43–47, and n. 22.
Hamdan has the better of this argument. Without reach
ing the question whether any provision of Commission Order
No. 1 is strictly “contrary to or inconsistent with” other pro
visions of the UCMJ, we conclude that the “practicability”
determination the President has made is insufficient to jus
tify variances from the procedures governing courts-martial.
Subsection (b) of Article 36 was added after World War II,
and requires a different showing of impracticability from the
one required by subsection (a). Subsection (a) requires that
the rules the President promulgates for courts-martial, pro
vost courts, and military commissions alike conform to those
that govern procedures in Article III courts, “so far as
he considers practicable.” 10 U. S. C. § 836(a) (emphasis
added). Subsection (b), by contrast, demands that the rules
applied in courts-martial, provost courts, and military com
missions—whether or not they conform with the Federal
Rules of Evidence—be “uniform insofar as practicable.”
§ 836(b) (emphasis added). Under the latter provision, then,
the rules set forth in the Manual for Courts-Martial must
apply to military commissions unless impracticable.50
50 Justice Thomas relies on the legislative history of the UCMJ to
argue that Congress’ adoption of Article 36(b) in the wake of World War
II was “motivated” solely by a desire for “uniformity across the separate
branches of the armed services.” Post, at 711. But even if Congress was

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
623 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
The President here has determined, pursuant to subsec
tion (a), that it is impracticable to apply the rules and princi
ples of law that govern “the trial of criminal cases in the
United States district courts,” § 836(a), to Hamdan’s commis
sion. We assume that complete deference is owed that de
termination. The President has not, however, made a simi
lar official determination that it is impracticable to apply the
rules for courts-martial.51 And even if subsection (b)’s re
quirements may be satisfied without such an official determi
nation, the requirements of that subsection are not satisfied
here.
Nothing in the record before us demonstrates that it would
be impracticable to apply court-martial rules in this case.
There is no suggestion, for example, of any logistical diffi
culty in securing properly sworn and authenticated evidence
or in applying the usual principles of relevance and admissi
bility. Assuming, arguendo, that the reasons articulated in
the President’s Article 36(a) determination ought to be con
sidered in evaluating the impracticability of applying court
martial rules, the only reason offered in support of that de
termination is the danger posed by international terrorism.52
concerned with ensuring uniformity across service branches, that does not
mean it did not also intend to codify the longstanding practice of proce
dural parity between courts-martial and other military tribunals. Indeed,
the suggestion that Congress did not intend uniformity across tribunal
types is belied by the textual proximity of subsection (a) (which requires
that the rules governing criminal trials in federal district courts apply,
absent the President’s determination of impracticability, to courts-martial,
provost courts, and military commissions alike) and subsection (b) (which
imposes the uniformity requirement).
51 We may assume that such a determination would be entitled to a
measure of deference. For the reasons given by Justice Kennedy, see
post, at 640 (opinion concurring in part), however, the level of deference
accorded to a determination made under subsection (b) presumably would
not be as high as that accorded to a determination under subsection (a).
52 Justice Thomas looks not to the President’s official Article 36(a) de
termination, but instead to press statements made by the Secretary of
Defense and the Under Secretary of Defense for Policy. See post, at
712–713 (dissenting opinion). We have not heretofore, in evaluating the

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
624 HAMDAN v. RUMSFELD
Opinion of the Court
Without for one moment underestimating that danger, it is
not evident to us why it should require, in the case of
Hamdan’s trial, any variance from the rules that govern
courts-martial.
The absence of any showing of impracticability is particu
larly disturbing when considered in light of the clear and
admitted failure to apply one of the most fundamental pro
tections afforded not just by the Manual for Courts-Martial
but also by the UCMJ itself: the right to be present. See
10 U. S. C. § 839(c) (2000 ed., Supp. V). Whether or not that
departure technically is “contrary to or inconsistent with”
the terms of the UCMJ, 10 U. S. C. § 836(a), the jettisoning
of so basic a right cannot lightly be excused as “practicable.”
Under the circumstances, then, the rules applicable in
courts-martial must apply. Since it is undisputed that Com
mission Order No. 1 deviates in many significant respects
from those rules, it necessarily violates Article 36(b).
The Government’s objection that requiring compliance
with the court-martial rules imposes an undue burden both
ignores the plain meaning of Article 36(b) and misunder
stands the purpose and the history of military commissions.
The military commission was not born of a desire to dispense
a more summary form of justice than is afforded by courts
martial; it developed, rather, as a tribunal of necessity to be
employed when courts-martial lacked jurisdiction over either
the accused or the subject matter. See Winthrop 831. Exi
gency lent the commission its legitimacy, but did not further
justify the wholesale jettisoning of procedural protections.
legality of executive action, deferred to comments made by such officials
to the media. Moreover, the only additional reason the comments pro
vide—aside from the general danger posed by international terrorism—
for departures from court-martial procedures is the need to protect classi
fied information. As we explain in the text, and as Justice Kennedy
elaborates in his separate opinion, the structural and procedural defects
of Hamdan’s commission extend far beyond rules preventing access to clas
sified information.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
625 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
That history explains why the military commission’s proce
dures typically have been the ones used by courts-martial.
That the jurisdiction of the two tribunals today may some
times overlap, see Madsen, 343 U. S., at 354, does not detract
from the force of this history; 53 Article 21 did not transform
the military commission from a tribunal of true exigency into
a more convenient adjudicatory tool. Article 36, confirming
as much, strikes a careful balance between uniform proce
dure and the need to accommodate exigencies that may
sometimes arise in a theater of war. That Article not hav
ing been complied with here, the rules specified for Hamdan’s
trial are illegal.54
D
The procedures adopted to try Hamdan also violate the
Geneva Conventions. The Court of Appeals dismissed
Hamdan’s Geneva Convention challenge on three independ
ent grounds: (1) the Geneva Conventions are not judicially
enforceable; (2) Hamdan in any event is not entitled to their
protections; and (3) even if he is entitled to their protections,
Councilman abstention is appropriate. Judge Williams,
concurring, rejected the second ground but agreed with the
53 Justice Thomas relies extensively on Madsen for the proposition
that the President has free rein to set the procedures that govern military
commissions. See post, at 706–707, 709, n. 16, 710, and 721. That reliance
is misplaced. Not only did Madsen not involve a law-of-war military com
mission, but (1) the petitioner there did not challenge the procedures used
to try her, (2) the UCMJ, with its new Article 36(b), did not become effec
tive until May 31, 1951, after the petitioner’s trial, see 343 U. S., at 345,
n. 6, and (3) the procedures used to try the petitioner actually afforded
more protection than those used in courts-martial, see id., at 358–360; see
also id., at 358 (“[T]he Military Government Courts for Germany . . . have
had a less military character than that of courts-martial”).
54 Prior to the enactment of Article 36(b), it may well have been the
case that a deviation from the rules governing courts-martial would not
have rendered the military commission “ ‘illegal.’ ” Post, at 707, n. 15
(Thomas, J., dissenting) (quoting Winthrop 841). Article 36(b), however,
imposes a statutory command that must be heeded.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
626 HAMDAN v. RUMSFELD
Opinion of the Court
majority respecting the first and the last. As we explained
in Part III, supra, the abstention rule applied in Council
man, 420 U. S. 738, is not applicable here.55 And for the
reasons that follow, we hold that neither of the other grounds
the Court of Appeals gave for its decision is persuasive.
i
The Court of Appeals relied on Johnson v. Eisentrager,
339 U. S. 763 (1950), to hold that Hamdan could not invoke
the Geneva Conventions to challenge the Government’s plan
to prosecute him in accordance with Commission Order
No. 1. Eisentrager involved a challenge by 21 German na
tionals to their 1945 convictions for war crimes by a military
tribunal convened in Nanking, China, and to their subse
quent imprisonment in occupied Germany. The petitioners
argued, inter alia, that the 1929 Geneva Convention ren
dered illegal some of the procedures employed during their
trials, which they said deviated impermissibly from the pro
cedures used by courts-martial to try American soldiers.
See id., at 789. We rejected that claim on the merits be
cause the petitioners (unlike Hamdan here) had failed to
identify any prejudicial disparity “between the Commission
that tried [them] and those that would try an offending sol
dier of the American forces of like rank,” and in any event
could claim no protection, under the 1929 Geneva Con
vention, during trials for crimes that occurred before their
confinement as prisoners of war. Id., at 790.56
55 Justice Thomas makes the different argument that Hamdan’s Ge
neva Convention challenge is not yet “ripe” because he has yet to be sen
tenced. See post, at 719–720. This is really just a species of the absten
tion argument we have already rejected. See Part III, supra. The text
of the Geneva Conventions does not direct an accused to wait until sen
tence is imposed to challenge the legality of the tribunal that is to try him.
56 As explained in Part VI–C, supra, that is no longer true under the
1949 Conventions.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
Cite as: 548 U. S. 557 (2006) 627
Opinion of the Court
Buried in a footnote of the opinion, however, is this curious
statement suggesting that the Court lacked power even to
consider the merits of the Geneva Convention argument:
“We are not holding that these prisoners have no right
which the military authorities are bound to respect.
The United States, by the Geneva Convention of July
27, 1929, 47 Stat. 2021, concluded with forty-six other
countries, including the German Reich, an agreement
upon the treatment to be accorded captives. These
prisoners claim to be and are entitled to its protection.
It is, however, the obvious scheme of the Agreement
that responsibility for observance and enforcement of
these rights is upon political and military authorities.
Rights of alien enemies are vindicated under it only
through protests and intervention of protecting powers
as the rights of our citizens against foreign governments
are vindicated only by Presidential intervention.” Id.,
at 789, n. 14.
The Court of Appeals, on the strength of this footnote, held
that “the 1949 Geneva Convention does not confer upon
Hamdan a right to enforce its provisions in court.” 415
F. 3d, at 40.
Whatever else might be said about the Eisentrager foot
note, it does not control this case. We may assume that “the
obvious scheme” of the 1949 Conventions is identical in all
relevant respects to that of the 1929 Geneva Convention,57
and even that that scheme would, absent some other provi
sion of law, preclude Hamdan’s invocation of the Convention’s
provisions as an independent source of law binding the Gov
57 But see, e. g., 4 Int’l Comm. of Red Cross, Commentary: Geneva Con
vention Relative to the Protection of Civilian Persons in Time of War 21
(J. Pictet gen. ed. 1958) (hereinafter GCIV Commentary) (the 1949 Geneva
Conventions were written “first and foremost to protect individuals, and
not to serve State interests”); GCIII Commentary 91 (“It was not . . . until
the Conventions of 1949 . . . that the existence of ‘rights’ conferred on
prisoners of war was affirmed”).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
628 HAMDAN v. RUMSFELD
Opinion of the Court
ernment’s actions and furnishing petitioner with any en
forceable right.58 For, regardless of the nature of the rights
conferred on Hamdan, cf. United States v. Rauscher, 119
U. S. 407 (1886), they are, as the Government does not dis
pute, part of the law of war. See Hamdi, 542 U. S., at 520–
521 (plurality opinion). And compliance with the law of war
is the condition upon which the authority set forth in Article
21 is granted.
ii
For the Court of Appeals, acknowledgment of that condi
tion was no bar to Hamdan’s trial by commission. As an
alternative to its holding that Hamdan could not invoke the
Geneva Conventions at all, the Court of Appeals concluded
that the Conventions did not in any event apply to the armed
conflict during which Hamdan was captured. The court ac
cepted the Executive’s assertions that Hamdan was captured
in connection with the United States’ war with al Qaeda and
that that war is distinct from the war with the Taliban in
Afghanistan. It further reasoned that the war with al
Qaeda evades the reach of the Geneva Conventions. See 415
F. 3d, at 41–42. We, like Judge Williams, disagree with the
latter conclusion.
The conflict with al Qaeda is not, according to the Gov
ernment, a conflict to which the full protections afforded de
tainees under the 1949 Geneva Conventions apply because
Article 2 of those Conventions (which appears in all four
Conventions) renders the full protections applicable only to
“all cases of declared war or of any other armed conflict
which may arise between two or more of the High Contract
58 But see generally Brief for Louis Henkin et al. as Amici Curiae; 1
Int’l Comm. of Red Cross, Commentary: Geneva Convention for the Ame
lioration of the Condition of the Wounded and Sick in Armed Forces in
the Field 84 (1952) (“It should be possible in States which are parties to
the Convention . . . for the rules of the Convention . . . to be evoked before
an appropriate national court by the protected person who has suffered
the violation”); GCIII Commentary 92; GCIV Commentary 79.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
629 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
ing Parties.” 6 U. S. T., at 3318.59 Since Hamdan was cap
tured and detained incident to the conflict with al Qaeda and
not the conflict with the Taliban, and since al Qaeda, unlike
Afghanistan, is not a “High Contracting Party”—i. e., a sig
natory of the Conventions, the protections of those Conven
tions are not, it is argued, applicable to Hamdan.60
We need not decide the merits of this argument because
there is at least one provision of the Geneva Conventions
that applies here even if the relevant conflict is not one be
tween signatories.61 Article 3, often referred to as Common
Article 3 because, like Article 2, it appears in all four Geneva
Conventions, provides that in a “conflict not of an interna
tional character occurring in the territory of one of the High
Contracting Parties, each Party[62] to the conflict shall be
bound to apply, as a minimum,” certain provisions protecting
“[p]ersons taking no active part in the hostilities, including
59 For convenience’s sake, we use citations to the Third Geneva Conven
tion only.
60 The President has stated that the conflict with the Taliban is a conflict
to which the Geneva Conventions apply. See White House Memorandum,
Humane Treatment of Taliban and al Qaeda Detainees 2 (Feb. 7, 2002),
available at http://www.justicescholars.org/pegc/archive/White_House/
bush_memo_20020207_ed.pdf.
61 Hamdan observes that Article 5 of the Third Geneva Convention re
quires that if there be “any doubt” whether he is entitled to prisoner-of
war protections, he must be afforded those protections until his status
is determined by a “competent tribunal.” 6 U. S. T., at 3324. See also
Headquarters Depts. of Army, Navy, Air Force, and Marine Corps, Army
Regulation 190–8, Enemy Prisoners of War, Retained Personnel, Civilian
Internees and Other Detainees (1997), App. 116. Because we hold that
Hamdan may not, in any event, be tried by the military commission the
President has convened pursuant to the November 13 Order and Commis
sion Order No. 1, the question whether his potential status as a prisoner
of war independently renders illegal his trial by military commission may
be reserved.
62 The term “Party” here has the broadest possible meaning; a Party
need neither be a signatory of the Convention nor “even represent a
legal entity capable of undertaking international obligations.” GCIII
Commentary 37.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
630 HAMDAN v. RUMSFELD
Opinion of the Court
members of armed forces who have laid down their arms and
those placed hors de combat by . . . detention.” Ibid. One
such provision prohibits “the passing of sentences and the
carrying out of executions without previous judgment pro
nounced by a regularly constituted court affording all the
judicial guarantees which are recognized as indispensable by
civilized peoples.” Id., at 3320.
The Court of Appeals thought, and the Government as
serts, that Common Article 3 does not apply to Hamdan be
cause the conflict with al Qaeda, being “ ‘international in
scope,’ ” does not qualify as a “ ‘conflict not of an interna
tional character.’ ” 415 F. 3d, at 41. That reasoning is erro
neous. The term “conflict not of an international character”
is used here in contradistinction to a conflict between na
tions. So much is demonstrated by the “fundamental logic
[of] the Convention’s provisions on its application.” Id., at
44 (Williams, J., concurring). Common Article 2 provides
that “the present Convention shall apply to all cases of de
clared war or of any other armed conflict which may arise
between two or more of the High Contracting Parties.” 6
U. S. T., at 3318 (Art. 2, ¶ 1). High Contracting Parties (sig
natories) also must abide by all terms of the Conventions
vis-a` -vis one another even if one party to the conflict is a
nonsignatory “Power,” and must so abide vis-a` -vis the non
signatory if “the latter accepts and applies” those terms.
Ibid. (Art. 2, ¶ 3). Common Article 3, by contrast, affords
some minimal protection, falling short of full protection
under the Conventions, to individuals associated with neither
a signatory nor even a nonsignatory “Power” who are in
volved in a conflict “in the territory of ” a signatory. The
latter kind of conflict is distinguishable from the conflict de
scribed in Common Article 2 chiefly because it does not in
volve a clash between nations (whether signatories or not).
In context, then, the phrase “not of an international charac
ter” bears its literal meaning. See, e. g., J. Bentham, Intro
duction to the Principles of Morals and Legislation 6, 296 (J.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
631 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
Burns & H. Hart eds. 1970) (using the term “international
law” as a “new though not inexpressive appellation” meaning
“betwixt nation and nation”; defining “international” to in
clude “mutual transactions between sovereigns as such”);
Int’l Comm. of Red Cross, Commentary on the Additional
Protocols to the Geneva Conventions of 12 August 1949,
p. 1351 (1987) (“[A] non-international armed conflict is dis
tinct from an international armed conflict because of the
legal status of the entities opposing each other”).
Although the official commentaries accompanying Com
mon Article 3 indicate that an important purpose of the pro
vision was to furnish minimal protection to rebels involved
in one kind of “conflict not of an international character,”
i. e., a civil war, see GCIII Commentary 36–37, the commen
taries also make clear “that the scope of application of the
Article must be as wide as possible,” id., at 36.63 In fact,
limiting language that would have rendered Common Article
3 applicable “especially [to] cases of civil war, colonial con
flicts, or wars of religion” was omitted from the final version
of the Article, which coupled broader scope of application
with a narrower range of rights than did earlier proposed
iterations. See id., at 42–43.
iii
Common Article 3, then, is applicable here and, as indi
cated above, requires that Hamdan be tried by a “regularly
63 See also id., at 35 (Common Article 3 “has the merit of being simple
and clear. . . . Its observance does not depend upon preliminary discussions
on the nature of the conflict”); GCIV Commentary 51 (“[N]obody in enemy
hands can be outside the law”); U. S. Army Judge Advocate General’s
Legal Center and School, Dept. of the Army, Law of War Workshop Desk
book 228 (June 2000) (reprint 2004) (Common Article 3 “serves as a ‘mini
mum yardstick of protection’ in all conflicts, not just internal armed con
flicts” (quoting Nicaragua v. United States, 1986 I. C. J. 14, ¶ 218, 25
I. L. M. 1023)); Prosecutor v. Tadic´, Case No. IT–94–1, Decision on the
Defence Motion for Interlocutory Appeal on Jurisdiction, ¶ 102 (ICTY
App. Chamber, Oct. 2, 1995) (stating that “the character of the conflict is
irrelevant” in deciding whether Common Article 3 applies).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
632 HAMDAN v. RUMSFELD
Opinion of the Court
constituted court affording all the judicial guarantees which
are recognized as indispensable by civilized peoples.” 6
U. S. T., at 3320 (Art. 3, ¶ 1(d)). While the term “regularly
constituted court” is not specifically defined in either Com
mon Article 3 or its accompanying commentary, other
sources disclose its core meaning. The commentary accom
panying a provision of the Fourth Geneva Convention, for
example, defines “ ‘regularly constituted’ ” tribunals to in
clude “ordinary military courts” and “definitely exclud[e] all
special tribunals.” GCIV Commentary 340 (defining the
term “properly constituted” in Article 66, which the com
mentary treats as identical to “regularly constituted”); 64 see
also Yamashita, 327 U. S., at 44 (Rutledge, J., dissenting) (de
scribing military commission as a court “specially constituted
for the particular trial”). And one of the Red Cross’ own
treatises defines “regularly constituted court” as used in
Common Article 3 to mean “established and organised in ac
cordance with the laws and procedures already in force in
a country.” Int’l Comm. of Red Cross, 1 Customary Int’l
Humanitarian Law 355 (2005); see also GCIV Commentary
340 (observing that “ordinary military courts” will “be set
up in accordance with the recognized principles governing
the administration of justice”).
The Government offers only a cursory defense of Hamdan’s
military commission in light of Common Article 3. See
Brief for Respondents 49–50. As Justice Kennedy ex
plains, that defense fails because “[t]he regular military
courts in our system are the courts-martial established by
congressional statutes.” Post, at 644 (opinion concurring in
part). At a minimum, a military commission “can be ‘regu
larly constituted’ by the standards of our military justice sys
64 The commentary’s assumption that the terms “properly constituted”
and “regularly constituted” are interchangeable is beyond reproach; the
French version of Article 66, which is equally authoritative, uses the term
“re´ gulie` rement constitue´ s” in place of “properly constituted.” 6 U. S. T.,
at 3559.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
633 Cite as: 548 U. S. 557 (2006)
Opinion of Stevens, J.
tem only if some practical need explains deviations from
court-martial practice.” Post, at 645. As we have ex
plained, see Part VI–C, supra, no such need has been demon
strated here.65
iv
Inextricably intertwined with the question of regular con
stitution is the evaluation of the procedures governing the
tribunal and whether they afford “all the judicial guarantees
which are recognized as indispensable by civilized peoples.”
6 U. S. T., at 3320 (Art. 3, ¶ 1(d)). Like the phrase “regu
larly constituted court,” this phrase is not defined in the text
of the Geneva Conventions. But it must be understood
to incorporate at least the barest of those trial protections
that have been recognized by customary international law.
Many of these are described in Article 75 of Protocol I to the
Geneva Conventions of 1949, adopted in 1977 (Protocol I).
Although the United States declined to ratify Protocol I, its
objections were not to Article 75 thereof. Indeed, it appears
that the Government “regard[s] the provisions of Article 75
as an articulation of safeguards to which all persons in the
hands of an enemy are entitled.” Taft, The Law of Armed
Conflict After 9/11: Some Salient Features, 28 Yale J. Int’l L.
319, 322 (2003). Among the rights set forth in Article 75 is
the “right to be tried in [one’s] presence.” Protocol I, Art.
75(4)(e).66
65 Further evidence of this tribunal’s irregular constitution is the fact
that its rules and procedures are subject to change midtrial, at the whim
of the Executive. See Commission Order No. 1, § 11 (providing that the
Secretary of Defense may change the governing rules “from time to
time”).
66 Other international instruments to which the United States is a signa
tory include the same basic protections set forth in Article 75. See, e. g.,
International Covenant on Civil and Political Rights, Art. 14, ¶ 3(d), Mar.
23, 1976, 999 U. N. T. S. 171 (setting forth the right of an accused “[t]o be
tried in his presence, and to defend himself in person or through legal
assistance of his own choosing”). Following World War II, several
defendants were tried and convicted by military commission for violations

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
634 HAMDAN v. RUMSFELD
Opinion of Stevens, J.
We agree with Justice Kennedy that the procedures
adopted to try Hamdan deviate from those governing
courts-martial in ways not justified by any “evident practical
need,” post, at 647, and for that reason, at least, fail to afford
the requisite guarantees. See post, at 646–653. We add
only that, as noted in Part VI–A, supra, various provisions
of Commission Order No. 1 dispense with the principles, ar
ticulated in Article 75 and indisputably part of the customary
international law, that an accused must, absent disruptive
conduct or consent, be present for his trial and must be privy
to the evidence against him. See §§ 6(B)(3), (D).67 That the
of the law of war in their failure to afford captives fair trials before imposi
tion and execution of sentence. In two such trials, the prosecutors argued
that the defendants’ failure to apprise accused individuals of all evidence
against them constituted violations of the law of war. See 5 U. N. War
Crimes Commission, Law Reports of Trials of War Criminals 25, 30 (1948)
(reprint 1997) (trial of Sergeant-Major Shigeru Ohashi), 66, 75 (trial of
General Tanaka Hisakasu).
67 The Government offers no defense of these procedures other than to
observe that the defendant may not be barred from access to evidence if
such action would deprive him of a “full and fair trial.” Commission
Order No. 1, § 6(D)(5)(b). But the Government suggests no circumstances
in which it would be “fair” to convict the accused based on evidence he
has not seen or heard. Cf. Crawford v. Washington, 541 U. S. 36, 49 (2004)
(“ ‘It is a rule of the common law, founded on natural justice, that no man
shall be prejudiced by evidence which he had not the liberty to cross
examine’ ” (quoting State v. Webb, 2 N. C. 103, 104 (Super. L. & Eq. 1794)
(per curiam)); Diaz v. United States, 223 U. S. 442, 455 (1912) (describing
the right to be present as “scarcely less important to the accused than the
right of trial itself ”); Lewis v. United States, 146 U. S. 370, 372 (1892)
(exclusion of defendant from part of proceedings is “contrary to the dic
tates of humanity” (internal quotation marks omitted)); Joint Anti-Fascist
Refugee Comm. v. McGrath, 341 U. S. 123, 170, n. 17, 171 (1951) (Frank
furter, J., concurring) (“The plea that evidence of guilt must be secret is
abhorrent to free men” (internal quotation marks omitted)). More funda
mentally, the legality of a tribunal under Common Article 3 cannot be
established by bare assurances that, whatever the character of the court
or the procedures it follows, individual adjudicators will act fairly.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
635 Cite as: 548 U. S. 557 (2006)
Opinion of the Court
Government has a compelling interest in denying Hamdan
access to certain sensitive information is not doubted.
Cf. post, at 723–724 (Thomas, J., dissenting). But, at least
absent express statutory provision to the contrary, informa
tion used to convict a person of a crime must be disclosed
to him.
v
Common Article 3 obviously tolerates a great degree of
flexibility in trying individuals captured during armed con
flict; its requirements are general ones, crafted to accommo
date a wide variety of legal systems. But requirements
they are nonetheless. The commission that the Presi
dent has convened to try Hamdan does not meet those
requirements.
VII
We have assumed, as we must, that the allegations made
in the Government’s charge against Hamdan are true. We
have assumed, moreover, the truth of the message implicit
in that charge—viz., that Hamdan is a dangerous individual
whose beliefs, if acted upon, would cause great harm and
even death to innocent civilians, and who would act upon
those beliefs if given the opportunity. It bears emphasizing
that Hamdan does not challenge, and we do not today ad
dress, the Government’s power to detain him for the dura
tion of active hostilities in order to prevent such harm. But
in undertaking to try Hamdan and subject him to criminal
punishment, the Executive is bound to comply with the rule
of law that prevails in this jurisdiction.
The judgment of the Court of Appeals is reversed, and the
case is remanded for further proceedings.
It is so ordered.
The Chief Justice took no part in the consideration or
decision of this case.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
636 HAMDAN v. RUMSFELD
Kennedy, J., concurring in part
Justice Breyer, with whom Justice Kennedy, Justice
Souter, and Justice Ginsburg join, concurring.
The dissenters say that today’s decision would “sorely
hamper the President’s ability to confront and defeat a new
and deadly enemy.” Post, at 705 (opinion of Thomas, J.).
They suggest that it undermines our Nation’s ability to “pre
ven[t] future attacks” of the grievous sort that we have al
ready suffered. Post, at 724. That claim leads me to state
briefly what I believe the majority sets forth both explicitly
and implicitly at greater length. The Court’s conclusion ul
timately rests upon a single ground: Congress has not issued
the Executive a “blank check.” Cf. Hamdi v. Rumsfeld, 542
U. S. 507, 536 (2004) (plurality opinion). Indeed, Congress
has denied the President the legislative authority to create
military commissions of the kind at issue here. Nothing
prevents the President from returning to Congress to seek
the authority he believes necessary.
Where, as here, no emergency prevents consultation with
Congress, judicial insistence upon that consultation does not
weaken our Nation’s ability to deal with danger. To the con
trary, that insistence strengthens the Nation’s ability to de
termine—through democratic means—how best to do so.
The Constitution places its faith in those democratic means.
Our Court today simply does the same.
Justice Kennedy, with whom Justice Souter, Justice
Ginsburg, and Justice Breyer join as to Parts I and II,
concurring in part.
Military Commission Order No. 1, which governs the mili
tary commission established to try petitioner Salim Hamdan
for war crimes, exceeds limits that certain statutes, duly
enacted by Congress, have placed on the President’s author
ity to convene military courts. This is not a case, then,
where the Executive can assert some unilateral authority to
fill a void left by congressional inaction. It is a case where
Congress, in the proper exercise of its powers as an inde

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
637 Cite as: 548 U. S. 557 (2006)
Kennedy, J., concurring in part
pendent branch of government, and as part of a long tradi
tion of legislative involvement in matters of military justice,
has considered the subject of military tribunals and set limits
on the President’s authority. Where a statute provides the
conditions for the exercise of governmental power, its re
quirements are the result of a deliberative and reflective
process engaging both of the political branches. Respect for
laws derived from the customary operation of the Executive
and Legislative Branches gives some assurance of stability
in time of crisis. The Constitution is best preserved by reli
ance on standards tested over time and insulated from the
pressures of the moment.
These principles seem vindicated here, for a case that may
be of extraordinary importance is resolved by ordinary rules.
The rules of most relevance here are those pertaining to
the authority of Congress and the interpretation of its
enactments.
It seems appropriate to recite these rather fundamental
points because the Court refers, as it should in its exposition
of the case, to the requirement of the Geneva Conventions of
1949 that military tribunals be “regularly constituted,” ante,
at 632—a requirement that controls here, if for no other rea
son, because Congress requires that military commissions
like the ones at issue conform to the “law of war,” 10 U. S. C.
§ 821. Whatever the substance and content of the term
“regularly constituted” as interpreted in this and any later
cases, there seems little doubt that it relies upon the impor
tance of standards deliberated upon and chosen in advance
of crisis, under a system where the single power of the Exec
utive is checked by other constitutional mechanisms. All of
which returns us to the point of beginning—that domestic
statutes control this case. If Congress, after due consider
ation, deems it appropriate to change the controlling stat
utes, in conformance with the Constitution and other laws,
it has the power and prerogative to do so.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
638 HAMDAN v. RUMSFELD
Kennedy, J., concurring in part
I join the Court’s opinion, save Parts V and VI–D–iv. To
state my reasons for this reservation, and to show my agree
ment with the remainder of the Court’s analysis by identify
ing particular deficiencies in the military commissions at
issue, this separate opinion seems appropriate.
I
Trial by military commission raises separation-of-powers
concerns of the highest order. Located within a single
branch, these courts carry the risk that offenses will be
defined, prosecuted, and adjudicated by executive officials
without independent review. Cf. Loving v. United States,
517 U. S. 748, 756–758, 760 (1996). Concentration of power
puts personal liberty in peril of arbitrary action by officials,
an incursion the Constitution’s three-part system is designed
to avoid. It is imperative, then, that when military tribu
nals are established, full and proper authority exists for the
Presidential directive.
The proper framework for assessing whether executive ac
tions are authorized is the three-part scheme used by Justice
Jackson in his opinion in Youngstown Sheet & Tube Co. v.
Sawyer, 343 U. S. 579 (1952). “When the President acts pur
suant to an express or implied authorization of Congress, his
authority is at its maximum, for it includes all that he pos
sesses in his own right plus all that Congress can delegate.”
Id., at 635. “When the President acts in absence of either a
congressional grant or denial of authority, he can only rely
upon his own independent powers, but there is a zone of twi
light in which he and Congress may have concurrent author
ity, or in which its distribution is uncertain.” Id., at 637.
And “[w]hen the President takes measures incompatible with
the expressed or implied will of Congress, his power is at its
lowest ebb.” Ibid.
In this case, as the Court observes, the President has acted
in a field with a history of congressional participation and
regulation. Ante, at 593, 619–620. In the Uniform Code

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
639 Cite as: 548 U. S. 557 (2006)
Kennedy, J., concurring in part
of Military Justice (UCMJ), 10 U. S. C. § 801 et seq., which
Congress enacted, building on earlier statutes, in 1950, see
Act of May 5, 1950, ch. 169, 64 Stat. 107, and later amended,
see, e. g., Military Justice Act of 1968, 82 Stat. 1335, Congress
has set forth governing principles for military courts. The
UCMJ as a whole establishes an intricate system of military
justice. It authorizes courts-martial in various forms, 10
U. S. C. §§ 816–820 (2000 ed. and Supp. III); it regulates the
organization and procedure of those courts, e. g., §§ 822–835,
851–854; it defines offenses, §§ 877–934, and rights for the
accused, e. g., §§ 827(b)–(c), 831, 844, 846, 855 (2000 ed.); and
it provides mechanisms for appellate review, §§ 859–876b
(2000 ed. and Supp. III). As explained below, the statute
further recognizes that special military commissions may be
convened to try war crimes. See infra, at 641; § 821 (2000
ed.). While these laws provide authority for certain forms
of military courts, they also impose limitations, at least two
of which control this case. If the President has exceeded
these limits, this becomes a case of conflict between Presi
dential and congressional action—a case within Justice Jack
son’s third category, not the second or first.
One limit on the President’s authority is contained in Arti
cle 36 of the UCMJ. That section provides:
“(a) Pretrial, trial, and post-trial procedures, including
modes of proof, for cases arising under this chapter tri
able in courts-martial, military commissions and other
military tribunals, and procedures for courts of inquiry,
may be prescribed by the President by regulations
which shall, so far as he considers practicable, apply the
principles of law and the rules of evidence generally rec
ognized in the trial of criminal cases in the United
States district courts, but which may not be contrary to
or inconsistent with this chapter.
“(b) All rules and regulations made under this article
shall be uniform insofar as practicable.” 10 U. S. C.
§ 836 (2000 ed.).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
640 HAMDAN v. RUMSFELD
Kennedy, J., concurring in part
In this provision the statute allows the President to imple
ment and build on the UCMJ’s framework by adopting proce
dural regulations, subject to three requirements: (1) Proce
dures for military courts must conform to district-court rules
insofar as the President “considers practicable”; (2) the pro
cedures may not be contrary to or inconsistent with the
provisions of the UCMJ; and (3) “insofar as practicable” all
rules and regulations under § 836 must be uniform, a require
ment, as the Court points out, that indicates the rules must
be the same for military commissions as for courts-martial
unless such uniformity is impracticable, ante, at 620, 622,
and n. 50.
As the Court further instructs, even assuming the first and
second requirements of § 836 are satisfied here—a matter of
some dispute, see ante, at 620–622—the third requires us to
compare the military-commission procedures with those for
courts-martial and determine, to the extent there are devia
tions, whether greater uniformity would be practicable.
Ante, at 623–625. Although we can assume the President’s
practicability judgments are entitled to some deference, the
Court observes that Congress’ choice of language in the uni
formity provision of 10 U. S. C. § 836(b) contrasts with the
language of § 836(a). This difference suggests, at the least,
a lower degree of deference for § 836(b) determinations.
Ante, at 623. The rules for military courts may depart from
federal-court rules whenever the President “considers” con
formity impracticable, § 836(a); but the statute requires pro
cedural uniformity across different military courts “insofar
as [uniformity is] practicable,” § 836(b), not insofar as the
President considers it to be so. The Court is right to con
clude this is of relevance to our decision. Further, as the
Court is also correct to conclude, ante, at 623–624, the term
“practicable” cannot be construed to permit deviations based
on mere convenience or expedience. “Practicable” means
“feasible,” that is, “possible to practice or perform” or “capa
ble of being put into practice, done, or accomplished.” Web

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
641 Cite as: 548 U. S. 557 (2006)
Kennedy, J., concurring in part
ster’s Third New International Dictionary 1780 (1961).
Congress’ chosen language, then, is best understood to allow
the selection of procedures based on logistical constraints,
the accommodation of witnesses, the security of the pro
ceedings, and the like. Insofar as the “[p]retrial, trial, and
post-trial procedures” for the military commissions at issue
deviate from court-martial practice, the deviations must be
explained by some such practical need.
In addition to § 836, a second UCMJ provision, 10 U. S. C.
§ 821, requires us to compare the commissions at issue to
courts-martial. This provision states:
“The provisions of this chapter conferring jurisdiction
upon courts-martial do not deprive military commis
sions, provost courts, or other military tribunals of con
current jurisdiction with respect to offenders or offenses
that by statute or by the law of war may be tried by
military commissions, provost courts, or other military
tribunals.”
In § 821 Congress has addressed the possibility that special
military commissions—criminal courts other than courts
martial—may at times be convened. At the same time,
however, the President’s authority to convene military com
missions is limited: It extends only to “offenders or offenses”
that “by statute or by the law of war may be tried by” such
military commissions. Ibid.; see also ante, at 593. The
Government does not claim to base the charges against Ham
dan on a statute; instead it invokes the law of war. That
law, as the Court explained in Ex parte Quirin, 317 U. S. 1
(1942), derives from “rules and precepts of the law of na
tions”; it is the body of international law governing armed
conflict. Id., at 28. If the military commission at issue is
illegal under the law of war, then an offender cannot be tried
“by the law of war” before that commission.
The Court is correct to concentrate on one provision of the
law of war that is applicable to our Nation’s armed conflict

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
642 HAMDAN v. RUMSFELD
Kennedy, J., concurring in part
with al Qaeda in Afghanistan and, as a result, to the use of
a military commission to try Hamdan. Ante, at 629–633; see
also 415 F. 3d 33, 44 (CADC 2005) (Williams, J., concurring).
That provision is Common Article 3 of the four Geneva Con
ventions of 1949. It prohibits, as relevant here, “the passing
of sentences and the carrying out of executions without pre
vious judgment pronounced by a regularly constituted court
affording all the judicial guarantees which are recognized as
indispensable by civilized peoples.” See, e. g., Article 3 of
the Geneva Convention (III) Relative to the Treatment of
Prisoners of War, Aug. 12, 1949, [1955] 6 U. S. T. 3316, 3318,
T. I. A. S. No. 3364. The provision is part of a treaty the
United States has ratified and thus accepted as binding law.
See id., at 3316. By Act of Congress, moreover, violations
of Common Article 3 are considered “war crimes,” punish
able as federal offenses, when committed by or against
United States nationals and military personnel. See 18
U. S. C. § 2441. There should be no doubt, then, that Com
mon Article 3 is part of the law of war as that term is used
in § 821.
The dissent by Justice Thomas argues that Common Ar
ticle 3 nonetheless is irrelevant to this case because in John
son v. Eisentrager, 339 U. S. 763 (1950), it was said to be the
“obvious scheme” of the 1929 Geneva Convention that
“[r]ights of alien enemies are vindicated under it only
through protests and intervention of protecting powers,”
i. e., signatory states, id., at 789, n. 14. As the Court ex
plains, ante, at 626–628, this language from Eisentrager is
not controlling here. Even assuming the Eisentrager analy
sis has some bearing upon the analysis of the broader 1949
Conventions and that, in consequence, rights are vindicated
“under [those Conventions]” only through protests and inter
vention, 339 U. S., at 789, n. 14, Common Article 3 is nonethe
less relevant to the question of authorization under § 821.
Common Article 3 is part of the law of war that Congress
has directed the President to follow in establishing military

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
Cite as: 548 U. S. 557 (2006) 643
Kennedy, J., concurring in part
commissions. Ante, at 629–630. Consistent with that view,
the Eisentrager Court itself considered on the merits claims
that “procedural irregularities” under the 1929 Convention
“deprive[d] the Military Commission of jurisdiction.” 339
U. S., at 789, 790.
In another military-commission case, In re Yamashita, 327
U. S. 1 (1946), the Court likewise considered on the merits—
without any caveat about remedies under the Convention—
a claim that an alleged violation of the 1929 Convention “es
tablish[ed] want of authority in the commission to proceed
with the trial.” Id., at 23, 24. That is the precise inquiry
we are asked to perform here.
Assuming the President has authority to establish a spe
cial military commission to try Hamdan, the commission
must satisfy Common Article 3’s requirement of a “regularly
constituted court affording all the judicial guarantees which
are recognized as indispensable by civilized peoples,” 6
U. S. T., at 3320. The terms of this general standard are yet
to be elaborated and further defined, but Congress has re
quired compliance with it by referring to the “law of war”
in § 821. The Court correctly concludes that the military
commission here does not comply with this provision.
Common Article 3’s standard of a “regularly constituted
court affording all the judicial guarantees which are recog
nized as indispensable by civilized peoples,” ibid., supports,
at the least, a uniformity principle similar to that codified
in § 836(b). The concept of a “regularly constituted court”
providing “indispensable” judicial guarantees requires con
sideration of the system of justice under which the commis
sion is established, though no doubt certain minimum stand
ards are applicable. See ante, at 632–633; 1 Int’l Comm. of
Red Cross, 1 Customary Int’l Humanitarian Law 355 (2005)
(explaining that courts are “regularly constituted” under
Common Article 3 if they are “established and organised in
accordance with the laws and procedures already in force in
a country”).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
644 HAMDAN v. RUMSFELD
Kennedy, J., concurring in part
The regular military courts in our system are the courts
martial established by congressional statutes. Acts of Con
gress confer on those courts the jurisdiction to try “any per
son” subject to war crimes prosecution. 10 U. S. C. § 818.
As the Court explains, moreover, while special military com
missions have been convened in previous armed conflicts—
a practice recognized in § 821—those military commissions
generally have adopted the structure and procedure of
courts-martial. See, e. g., 1 The War of the Rebellion: A
Compilation of the Official Records of the Union and Confed
erate Armies 248 (2d series 1894) (Civil War general order
requiring that military commissions “be constituted in a sim
ilar manner and their proceedings be conducted according to
the same general rules as courts-martial in order to prevent
abuses which might otherwise arise”); W. Winthrop, Military
Law and Precedents 835, n. 81 (rev. 2d ed. 1920) (“[M]ilitary
commissions are constituted and composed, and their pro
ceedings are conducted, similarly to general courts-martial”);
1 U. N. War Crimes Commission, Law Reports of Trials of
War Criminals 116–117 (1947) (reprint 1997) (hereinafter
Law Reports) (discussing post-World War II regulations re
quiring that military commissions “hav[e] regard for” rules
of procedure and evidence applicable in general courts
martial); see also ante, at 617–620; post, at 707, n. 15
(Thomas, J., dissenting). Today, moreover, § 836(b)—which
took effect after the military trials in the World War II cases
invoked by the dissent, see Madsen v. Kinsella, 343 U. S.
341, 344–345, and n. 6 (1952); Yamashita, supra, at 5; Quirin,
317 U. S., at 23—codifies this presumption of uniformity at
least as to “[p]retrial, trial, and post-trial procedures.” Ab
sent more concrete statutory guidance, this historical and
statutory background—which suggests that some practical
need must justify deviations from the court-martial model—
informs the understanding of which military courts are “reg
ularly constituted” under United States law.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
645 Cite as: 548 U. S. 557 (2006)
Kennedy, J., concurring in part
In addition, whether or not the possibility, contemplated
by the regulations here, of midtrial procedural changes could
by itself render a military commission impermissibly irregu
lar, ante, at 633, n. 65; see also Military Commission Order
No. 1, § 11 (Aug. 31, 2005), App. to Brief for Petitioner 46a–
72a (hereinafter MCO), an acceptable degree of independ
ence from the Executive is necessary to render a commission
“regularly constituted” by the standards of our Nation’s
system of justice. And any suggestion of executive power
to interfere with an ongoing judicial process raises concerns
about the proceedings’ fairness. Again, however, courts
martial provide the relevant benchmark. Subject to consti
tutional limitations, see Ex parte Milligan, 4 Wall. 2 (1866),
Congress has the power and responsibility to determine the
necessity for military courts, and to provide the jurisdiction
and procedures applicable to them. The guidance Congress
has provided with respect to courts-martial indicates the
level of independence and procedural rigor that Congress has
deemed necessary, at least as a general matter, in the mili
tary context.
At a minimum a military commission like the one at
issue—a commission specially convened by the President to
try specific persons without express congressional authoriza
tion—can be “regularly constituted” by the standards of our
military justice system only if some practical need explains
deviations from court-martial practice. In this regard the
standard of Common Article 3, applied here in conformity
with § 821, parallels the practicability standard of § 836(b).
Section 836, however, is limited by its terms to matters prop
erly characterized as procedural—that is, “[p]retrial, trial,
and post-trial procedures”—while Common Article 3 permits
broader consideration of matters of structure, organization,
and mechanisms to promote the tribunal’s insulation from
command influence. Thus the combined effect of the two
statutes discussed here—§§ 836 and 821—is that considera
tions of practicability must support departures from court

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
646 HAMDAN v. RUMSFELD
Kennedy, J., concurring in part
martial practice. Relevant concerns, as noted earlier, relate
to logistical constraints, accommodation of witnesses, secu
rity of the proceedings, and the like, not mere expedience or
convenience. This determination, of course, must be made
with due regard for the constitutional principle that con
gressional statutes can be controlling, including the congres
sional direction that the law of war has a bearing on the
determination.
These principles provide the framework for an analysis of
the specific military commission at issue here.
II
In assessing the validity of Hamdan’s military commission
the precise circumstances of this case bear emphasis. The
allegations against Hamdan are undoubtedly serious. Cap
tured in Afghanistan during our Nation’s armed conflict with
the Taliban and al Qaeda—a conflict that continues as we
speak—Hamdan stands accused of overt acts in furtherance
of a conspiracy to commit terrorism: delivering weapons and
ammunition to al Qaeda, acquiring trucks for use by Usama
bin Laden’s bodyguards, providing security services to bin
Laden, and receiving weapons training at a terrorist camp.
App. to Pet. for Cert. 65a–67a. Nevertheless, the circum
stances of Hamdan’s trial present no exigency requiring
special speed or precluding careful consideration of evidence.
For roughly four years, Hamdan has been detained at a
permanent United States military base in Guantanamo
Bay, Cuba. And regardless of the outcome of the criminal
proceedings at issue, the Government claims authority to
continue to detain him based on his status as an enemy
combatant.
Against this background, the Court is correct to conclude
that the military commission the President has convened to
try Hamdan is unauthorized. Ante, at 625, 631–633, 635.
The following analysis, which expands on the Court’s discus
sion, explains my reasons for reaching this conclusion.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
647 Cite as: 548 U. S. 557 (2006)
Kennedy, J., concurring in part
To begin with, the structure and composition of the mili
tary commission deviate from conventional court-martial
standards. Although these deviations raise questions about
the fairness of the trial, no evident practical need explains
them.
Under the UCMJ, courts-martial are organized by a “con
vening authority”—either a commanding officer, the Secre
tary of Defense, the Secretary concerned, or the President.
10 U. S. C. §§ 822–824 (2000 ed. and Supp. III). The conven
ing authority refers charges for trial, Manual for Courts-
Martial, United States, Rule for Courts-Martial 401 (2005
ed.) (hereinafter R. C. M.), and selects the court-martial
members who vote on the guilt or innocence of the accused
and determine the sentence, 10 U. S. C. §§ 825(d)(2), 851–852
(2000 ed.); R. C. M. 503(a). Paralleling this structure, under
MCO No. 1 an “ ‘Appointing Authority’ ”—either the Secre
tary of Defense or the Secretary’s “designee”—establishes
commissions subject to the order, MCO No. 1, § 2, approves
and refers charges to be tried by those commissions,
§ 4(B)(2)(a), and appoints commission members who vote on
the conviction and sentence, §§ 4(A) (1)–(3). In addition the
Appointing Authority determines the number of commission
members (at least three), oversees the chief prosecutor, pro
vides “investigative or other resources” to the defense inso
far as he or she “deems necessary for a full and fair trial,”
approves or rejects plea agreements, approves or disap
proves communications with news media by prosecution or
defense counsel (a function shared by the General Counsel of
the Department of Defense), and issues supplementary com
mission regulations (subject to approval by the General
Counsel of the Department of Defense, unless the Appointing
Authority is the Secretary of Defense). See MCO No. 1,
§§ 4(A)(2), 5(H), 6(A)(4), 7(A); Military Commission Instruc
tion No. 3, § 5(C) (July 15, 2005) (hereinafter MCI), avail
able at www.defenselink.mil/news/Aug2005/d20050811MCI3.
pdf; MCI No. 4, § 5(C) (Sept. 16, 2005), available at www.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
648 HAMDAN v. RUMSFELD
Kennedy, J., concurring in part
defenselink.mil/news/Oct2005/d20051003MCI4.pdf; MCI No.
6, § 3(B)(3) (Apr. 15, 2004), available at www.defenselink.mil/
news/Apr2004/d20040420ins6.pdf (all Internet materials as
visited June 27, 2006, and available in Clerk of Court’s case
file).
Against the background of these significant powers for the
Appointing Authority, which in certain respects at least con
form to ordinary court-martial standards, the regulations
governing the commissions at issue make several noteworthy
departures. At a general court-martial—the only type au
thorized to impose penalties of more than one year’s incar
ceration or to adjudicate offenses against the law of war,
R. C. M. 201(f); 10 U. S. C. §§ 818–820 (2000 ed. and Supp.
III)—the presiding officer who rules on legal issues must be
a military judge. R. C. M. 501(a)(1), 801(a)(4)–(5); 10 U. S. C.
§ 816(1) (2000 ed., Supp. III); see also R. C. M. 201(f)(2)(B)(ii)
(likewise requiring a military judge for certain other courts
martial); 10 U. S. C. § 819 (2000 ed. and Supp. III) (same). A
military judge is an officer who is a member of a state or
federal bar and has been specially certified for judicial duties
by the Judge Advocate General for the officer’s Armed Serv
ice. R. C. M. 502(c); 10 U. S. C. § 826(b). To protect their
independence, military judges at general courts-martial
are “assigned and directly responsible to the Judge Advo
cate General or the Judge Advocate General’s designee.”
R. C. M. 502(c). They must be detailed to the court, in ac
cordance with applicable regulations, “by a person assigned
as a military judge and directly responsible to the Judge Ad
vocate General or the Judge Advocate General’s designee.”
R. C. M. 503(b); see also 10 U. S. C. § 826(c); see generally
Weiss v. United States, 510 U. S. 163, 179–181 (1994) (discuss
ing provisions that “insulat[e] military judges from the ef
fects of command influence” and thus “preserve judicial im
partiality”). Here, by contrast, the Appointing Authority
selects the presiding officer, MCO No. 1, §§ 4(A)(1), (A)(4);

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
649 Cite as: 548 U. S. 557 (2006)
Kennedy, J., concurring in part
and that officer need only be a judge advocate, that is, a
military lawyer, § 4(A)(4).
The Appointing Authority, moreover, exercises supervi
sory powers that continue during trial. Any interlocutory
question “the disposition of which would effect a termination
of proceedings with respect to a charge” is subject to deci
sion not by the presiding officer, but by the Appointing Au
thority. § 4(A)(5)(e) (stating that the presiding officer “shall
certify” such questions to the Appointing Authority). Other
interlocutory questions may be certified to the Appointing
Authority as the presiding officer “deems appropriate.”
Ibid. While in some circumstances the Government may
appeal certain rulings at a court-martial—including “an
order or ruling that terminates the proceedings with re
spect to a charge or specification,” R. C. M. 908(a); see also
10 U. S. C. § 862(a)—the appeals go to a body called the
Court of Criminal Appeals, not to the convening authority.
R. C. M. 908; 10 U. S. C. § 862(b); see also R. C. M. 1107 (re
quiring the convening authority to approve or disapprove the
findings and sentence of a court-martial but providing for
such action only after entry of sentence and restricting
actions that increase penalties); 10 U. S. C. § 860 (same);
cf. § 837(a) (barring command influence on court-martial ac
tions). The Court of Criminal Appeals functions as the mili
tary’s intermediate appeals court; it is established by the
Judge Advocate General for each Armed Service and com
posed of appellate military judges. R. C. M. 1203; 10 U. S. C.
§ 866. This is another means in which, by structure and tra
dition, the court-martial process is insulated from those who
have an interest in the outcome of the proceedings.
Finally, in addition to these powers with respect to the
presiding officer, the Appointing Authority has greater flex
ibility in appointing commission members. While a general
court-martial requires, absent a contrary election by the ac
cused, at least five members, R. C. M. 501(a)(1); 10 U. S. C.
§ 816(1) (2000 ed. and Supp. III), the Appointing Authority

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
650 HAMDAN v. RUMSFELD
Kennedy, J., concurring in part
here is free, as noted earlier, to select as few as three. MCO
No. 1, § 4(A)(2). This difference may affect the deliberative
process and the prosecution’s burden of persuasion.
As compared to the role of the convening authority in a
court-martial, the greater powers of the Appointing Author
ity here—including even the resolution of dispositive issues
in the middle of the trial—raise concerns that the commis
sion’s decisionmaking may not be neutral. If the differences
are supported by some practical need beyond the goal of con
stant and ongoing supervision, that need is neither appar
ent from the record nor established by the Government’s
submissions.
It is no answer that, at the end of the day, the Detainee
Treatment Act of 2005 (DTA), 119 Stat. 2739, affords
military-commission defendants the opportunity for judicial
review in federal court. As the Court is correct to observe,
the scope of that review is limited, DTA § 1005(e)(3)(D), id.,
at 2743; see also ante, at 573–574, and the review is not
automatic if the defendant’s sentence is under 10 years,
§ 1005(e)(3)(B), 119 Stat. 2743. Also, provisions for review
of legal issues after trial cannot correct for structural de
fects, such as the role of the Appointing Authority, that can
cast doubt on the factfinding process and the presiding
judge’s exercise of discretion during trial. Before military
commission defendants may obtain judicial review, further
more, they must navigate a military review process that
again raises fairness concerns. At the outset, the Appoint
ing Authority (unless the Appointing Authority is the Sec
retary of Defense) performs an “administrative review” of
undefined scope, ordering any “supplementary proceedings”
deemed necessary. MCO No. 1, § 6(H)(3). After that the
case is referred to a three-member Review Panel com
posed of officers selected by the Secretary of Defense.
§ 6(H)(4); MCI No. 9, § 4(B) (Oct. 11, 2005), available at
www.defenselink.mil/news/Oct2005/d20051014MCI9.pdf.
Though the Review Panel may return the case for further

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
651 Cite as: 548 U. S. 557 (2006)
Kennedy, J., concurring in part
proceedings only if a majority “form[s] a definite and firm
conviction that a material error of law occurred,” MCO No. 1,
§ 6(H)(4); MCI No. 9, § 4(C)(1)(a), only one member must have
“experience as a judge,” MCO No. 1, § 6(H)(4); nothing in the
regulations requires that other panel members have legal
training. By comparison to the review of court-martial
judgments performed by such independent bodies as the
Judge Advocate General, the Court of Criminal Appeals, and
the Court of Appeals for the Armed Forces, 10 U. S. C.
§§ 862, 864, 866, 867, 869, the review process here lacks struc
tural protections designed to help ensure impartiality.
These structural differences between the military commis
sions and courts-martial—the concentration of functions, in
cluding legal decisionmaking, in a single executive official;
the less rigorous standards for composition of the tribunal;
and the creation of special review procedures in place of in
stitutions created and regulated by Congress—remove safe
guards that are important to the fairness of the proceedings
and the independence of the court. Congress has prescribed
these guarantees for courts-martial; and no evident practical
need explains the departures here. For these reasons the
commission cannot be considered regularly constituted under
United States law and thus does not satisfy Congress’ re
quirement that military commissions conform to the law
of war.
Apart from these structural issues, moreover, the basic
procedures for the commissions deviate from procedures for
courts-martial, in violation of § 836(b). As the Court ex
plains, ante, at 614–615, 623, the MCO abandons the detailed
Military Rules of Evidence, which are modeled on the Fed
eral Rules of Evidence in conformity with § 836(a)’s require
ment of presumptive compliance with district-court rules.
Instead, the order imposes just one evidentiary rule: “Evi
dence shall be admitted if . . . the evidence would have proba
tive value to a reasonable person,” MCO No. 1, § 6(D)(1).
Although it is true some military commissions applied

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
652 HAMDAN v. RUMSFELD
Kennedy, J., concurring in part
an amorphous evidence standard in the past, see, e. g., 1
Law Reports 117–118 (discussing World War II military
commission orders); Exec. Order No. 9185, 7 Fed. Reg. 5103
(1942) (order convening military commission to try Nazi sab
oteurs), the evidentiary rules for those commissions were
adopted before Congress enacted the uniformity require
ment of 10 U. S. C. § 836(b) as part of the UCMJ, see Act of
May 5, 1950, ch. 169, 64 Stat. 107, 120, 149. And while some
flexibility may be necessary to permit trial of battlefield
captives like Hamdan, military statutes and rules already
provide for introduction of deposition testimony for absent
witnesses, 10 U. S. C. § 849(d); R. C. M. 702, and use of clas
sified information, Military Rule Evid. 505. Indeed, the
deposition-testimony provision specifically mentions military
commissions and thus is one of the provisions the Govern
ment concedes must be followed by the commission at issue.
See ante, at 621, and n. 49. That provision authorizes ad
mission of deposition testimony only if the witness is absent
for specified reasons, § 849(d)—a requirement that makes no
sense if military commissions may consider all probative evi
dence. Whether or not this conflict renders the rules at
issue “contrary to or inconsistent with” the UCMJ under
§ 836(a), it creates a uniformity problem under § 836(b).
The rule here could permit admission of multiple hearsay
and other forms of evidence generally prohibited on grounds
of unreliability. Indeed, the commission regulations spe
cifically contemplate admission of unsworn written state
ments, MCO No. 1, § 6(D)(3); and they make no provision for
exclusion of coerced declarations save those “established
to have been made as a result of torture,” MCI No. 10,
§ 3(A) (Mar. 24, 2006), available at www.defenselink.mil/
news/Mar2006/d20060327MCI10.pdf; cf. Military Rule Evid.
304(c)(3) (generally barring use of statements obtained
“through the use of coercion, unlawful influence, or unlawful
inducement”); 10 U. S. C. § 831(d) (same). Besides, even if

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
653 Cite as: 548 U. S. 557 (2006)
Kennedy, J., concurring in part
evidence is deemed nonprobative by the presiding officer at
Hamdan’s trial, the military-commission members still may
view it. In another departure from court-martial practice
the military-commission members may object to the presid
ing officer’s evidence rulings and determine themselves, by
majority vote, whether to admit the evidence. MCO No. 1,
§ 6(D)(1); cf. R. C. M. 801(a)(4), (e)(1) (providing that the mili
tary judge at a court-martial determines all questions of
law).
As the Court explains, the Government has made no dem
onstration of practical need for these special rules and proce
dures, either in this particular case or as to the military com
missions in general, ante, at 622–624; nor is any such need
self-evident. For all the Government’s regulations and sub
missions reveal, it would be feasible for most, if not all, of
the conventional military evidence rules and procedures to
be followed.
In sum, as presently structured, Hamdan’s military com
mission exceeds the bounds Congress has placed on the Pres
ident’s authority in Articles 36 and 21 of the UCMJ, 10
U. S. C. §§ 836, 821. Because Congress has prescribed these
limits, Congress can change them, requiring a new analysis
consistent with the Constitution and other governing laws.
At this time, however, we must apply the standards Con
gress has provided. By those standards the military com
mission is deficient.
III
In light of the conclusion that the military commission here
is unauthorized under the UCMJ, I see no need to consider
several further issues addressed in the plurality opinion by
Justice Stevens and the dissent by Justice Thomas.
First, I would not decide whether Common Article 3’s
standard—a “regularly constituted court affording all the ju
dicial guarantees which are recognized as indispensable by
civilized peoples,” 6 U. S. T., at 3320 (¶ (1)(d))—necessarily

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
654 HAMDAN v. RUMSFELD
Kennedy, J., concurring in part
requires that the accused have the right to be present at all
stages of a criminal trial. As Justice Stevens explains,
MCO No. 1 authorizes exclusion of the accused from the pro
ceedings if the presiding officer determines that, among
other things, protection of classified information so requires.
See §§ 6(B)(3), (D)(5); ante, at 613–614. Justice Stevens
observes that these regulations create the possibility of
a conviction and sentence based on evidence Hamdan has
not seen or heard—a possibility the plurality is correct to
consider troubling. Ante, at 634–635, and n. 67 (collect
ing cases); see also In re Oliver, 333 U. S. 257, 277 (1948)
(finding “no support for sustaining petitioner’s conviction
of contempt of court upon testimony given in petitioner’s
absence”).
As the dissent by Justice Thomas points out, however,
the regulations bar the presiding officer from admitting
secret evidence if doing so would deprive the accused of a
“full and fair trial.” MCO No. 1, § 6(D)(5)(b); see also post,
at 722–723. This fairness determination, moreover, is un
ambiguously subject to judicial review under the DTA. See
§ 1005(e)(3)(D)(i), 119 Stat. 2743 (allowing review of compli
ance with the “standards and procedures” in MCO No. 1).
The evidentiary proceedings at Hamdan’s trial have yet to
commence, and it remains to be seen whether he will suffer
any prejudicial exclusion.
There should be reluctance, furthermore, to reach unnec
essarily the question whether, as the plurality seems to con
clude, ante, at 633, Article 75 of Protocol I to the Geneva
Conventions is binding law notwithstanding the earlier deci
sion by our Government not to accede to the Protocol. For
all these reasons, and without detracting from the impor
tance of the right of presence, I would rely on other de
ficiencies noted here and in the opinion by the Court—defi
ciencies that relate to the structure and procedure of the
commission and that inevitably will affect the proceedings—
as the basis for finding the military commissions lack au

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
655 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
thorization under 10 U. S. C. § 836 and fail to be regularly
constituted under Common Article 3 and § 821.
I likewise see no need to address the validity of the con
spiracy charge against Hamdan—an issue addressed at
length in Part V of Justice Stevens’ opinion and in Part
II–C of Justice Thomas’ dissent. See ante, at 600–613;
post, at 689–704. In light of the conclusion that the military
commissions at issue are unauthorized, Congress may choose
to provide further guidance in this area. Congress, not the
Court, is the branch in the better position to undertake the
“sensitive task of establishing a principle not inconsistent
with the national interest or with international justice.”
Banco Nacional de Cuba v. Sabbatino, 376 U. S. 398, 428
(1964).
Finally, for the same reason, I express no view on the mer
its of other limitations on military commissions described as
elements of the common law of war in Part V of Justice
Stevens’ opinion. See ante, at 595–600, 611–613; post, at
683–689 (Thomas, J., dissenting).
With these observations I join the Court’s opinion with the
exception of Parts V and VI–D–iv.
Justice Scalia, with whom Justice Thomas and Jus
tice Alito join, dissenting.
On December 30, 2005, Congress enacted the Detainee
Treatment Act (DTA). It unambiguously provides that, as
of that date, “no court, justice, or judge” shall have jurisdic
tion to consider the habeas application of a Guantanamo Bay
detainee. Notwithstanding this plain directive, the Court
today concludes that, on what it calls the statute’s most natu
ral reading, every “court, justice, or judge” before whom
such a habeas application was pending on December 30 has
jurisdiction to hear, consider, and render judgment on it.
This conclusion is patently erroneous. And even if it were
not, the jurisdiction supposedly retained should, in an exer
cise of sound equitable discretion, not be exercised.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
656 HAMDAN v. RUMSFELD
Scalia, J., dissenting
I
A
The DTA provides: “[N]o court, justice, or judge shall have
jurisdiction to hear or consider an application for a writ of
habeas corpus filed by or on behalf of an alien detained by
the Department of Defense at Guantanamo Bay, Cuba.”
§ 1005(e)(1), 119 Stat. 2742 (internal division omitted). This
provision “t[ook] effect on the date of the enactment of this
Act,” § 1005(h)(1), id., at 2743, which was December 30, 2005.
As of that date, then, no court had jurisdiction to “hear or
consider” the merits of petitioner’s habeas application. This
repeal of jurisdiction is simply not ambiguous as between
pending and future cases. It prohibits any exercise of ju
risdiction, and it became effective as to all cases last Decem
ber 30. It is also perfectly clear that the phrase “no court,
justice, or judge” includes this Court and its Members, and
that by exercising our appellate jurisdiction in this case we
are “hear[ing] or consider[ing] . . . an application for a writ
of habeas corpus.”
An ancient and unbroken line of authority attests that
statutes ousting jurisdiction unambiguously apply to cases
pending at their effective date. For example, in Bruner v.
United States, 343 U. S. 112 (1952), we granted certiorari to
consider whether the Tucker Act’s provision denying district
court jurisdiction over suits by “officers” of the United
States barred a suit by an employee of the United States.
After we granted certiorari, Congress amended the Tucker
Act by adding suits by “ ‘employees’ ” to the provision bar
ring jurisdiction over suits by officers. Id., at 114. This
statute narrowing the jurisdiction of the district courts “be
came effective” while the case was pending before us, ibid.,
and made no explicit reference to pending cases. Because
the statute “did not reserve jurisdiction over pending cases,”
id., at 115, we held that it clearly ousted jurisdiction over
them. Summarizing centuries of practice, we said: “This

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
657 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
rule—that, when a law conferring jurisdiction is repealed
without any reservation as to pending cases, all cases fall
with the law—has been adhered to consistently by this
Court.” Id., at 116–117. See also Landgraf v. USI Film
Products, 511 U. S. 244, 274 (1994) (opinion for the Court by
Stevens, J.) (“We have regularly applied intervening stat
utes conferring or ousting jurisdiction, whether or not juris
diction lay when the underlying conduct occurred or when
the suit was filed”).
This venerable rule that statutes ousting jurisdiction ter
minate jurisdiction in pending cases is not, as today’s opinion
for the Court would have it, a judge-made “presumption
against jurisdiction,” ante, at 576, that we have invented to
resolve an ambiguity in the statutes. It is simple recogni
tion of the reality that the plain import of a statute repeal
ing jurisdiction is to eliminate the power to consider and ren
der judgment—in an already pending case no less than in a
case yet to be filed.
“Without jurisdiction the court cannot proceed at all in
any cause. Jurisdiction is power to declare the law, and
when it ceases to exist, the only function remaining to
the court is that of announcing the fact and dismissing
the cause. And this is not less clear upon authority
than upon principle.” Ex parte McCardle, 7 Wall. 506,
514 (1869) (emphasis added).
To alter this plain meaning, our cases have required an
explicit reservation of pending cases in the jurisdiction
repealing statute. For example, Bruner, as mentioned,
looked to whether Congress made “any reservation as to
pending cases.” 343 U. S., at 116–117; see also id., at 115
(“Congress made no provision for cases pending at the effec
tive date of the Act withdrawing jurisdiction and, for this
reason, Courts of Appeals ordered pending cases terminated
for want of jurisdiction”). Likewise, in Hallowell v. Com
mons, 239 U. S. 506 (1916), Justice Holmes relied on the fact

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
658 HAMDAN v. RUMSFELD
Scalia, J., dissenting
that the jurisdiction-ousting provision “made no exception
for pending litigation, but purported to be universal,” id., at
508. And in Insurance Co. v. Ritchie, 5 Wall. 541 (1867), we
again relied on the fact that the jurisdictional repeal was
made “without any saving of such causes as that before us,”
id., at 544. As in Bruner, Hallowell, and Ritchie, the DTA’s
directive that “no court, justice, or judge shall have jurisdic
tion,” § 1005(e)(1), 119 Stat. 2742, is made “without any reser
vation as to pending cases” and “purport[s] to be universal.”
What we stated in an earlier case remains true here:
“[W]hen, if it had been the intention to confine the operation
of [the jurisdictional repeal] . . . to cases not pending, it would
have been so easy to have said so, we must presume that
Congress meant the language employed should have its usual
and ordinary signification, and that the old law should be
unconditionally repealed.” Railroad Co. v. Grant, 98 U. S.
398, 403 (1879).
The Court claims that I “rea[d] too much into” the Bruner
line of cases, ante, at 577, n. 7, and that “the Bruner rule”
has never been “an inflexible trump,” ante, at 584. But the
Court sorely misdescribes Bruner—as if it were a kind of
early-day Lindh v. Murphy, 521 U. S. 320 (1997), resolving
statutory ambiguity by oblique negative inference. On the
contrary, as described above, Bruner stated its holding as an
unqualified “rule,” which “has been adhered to consistently
by this Court.” 343 U. S., at 116–117. Though Bruner re
ferred to an express saving clause elsewhere in the statute,
id., at 115, n. 7, it disavowed any reliance on such oblique
indicators to vary the plain meaning, quoting Ritchie at
length: “ ‘It is quite possible that this effect of the
[jurisdiction-stripping statute] was not contemplated by
Congress. . . . [B]ut when terms are unambiguous we may
not speculate on probabilities of intention.’ ” 343 U. S., at
116 (quoting 5 Wall., at 544–545).
The Court also attempts to evade the Bruner line of cases
by asserting that “the ‘presumption’ [of application to pend

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
659 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
ing cases] that these cases have applied is more accurately
viewed as the nonapplication of another presumption—viz.,
the presumption against retroactivity—in certain limited cir
cumstances.” Ante, at 576. I have already explained that
what the Court calls a “presumption” is simply the acknowl
edgment of the unambiguous meaning of such provisions.
But even taking it to be what the Court says, the effect upon
the present case would be the same. Prospective applica
tions of a statute are “effective” upon the statute’s effective
date; that is what an effective-date provision like § 1005(h)(1)
means.1 “ ‘[S]hall take effect upon enactment’ is presumed
to mean ‘shall have prospective effect upon enactment,’ and
that presumption is too strong to be overcome by any nega
tive inference [drawn from other provisions of the statute].”
Landgraf, supra, at 288 (Scalia, J., concurring in judg
ments). The Court’s “nonapplication of . . . the presumption
against retroactivity” to § 1005(e)(1) is thus just another way
of stating that the statute takes immediate effect in pend
ing cases.
Though the Court resists the Bruner rule, it cannot cite a
single case in the history of Anglo-American law (before
1 The Court apparently believes that the effective-date provision means
nothing at all. “That paragraph (1), along with paragraphs (2) and (3), is
to ‘take effect on the date of the enactment,’ DTA § 1005(h)(1), 119 Stat.
2743, is not dispositive,” says the Court, ante, at 579, n. 9. The Court’s
authority for this conclusion is its quote from INS v. St. Cyr, 533 U. S. 289,
317 (2001), to the effect that “a statement that a statute will become effec
tive on a certain date does not even arguably suggest that it has any
application to conduct that occurred at an earlier date.” Ante, at 579,
n. 9 (emphasis added and internal quotation marks omitted). But this
quote merely restates the obvious: An effective-date provision does not
render a statute applicable to “conduct that occurred at an earlier date,”
but of course it renders the statute applicable to conduct that occurs
on the effective date and all future dates—such as the Court’s exercise
of jurisdiction here. The Court seems to suggest that, because the
effective-date provision does not authorize retroactive application, it also
fails to authorize prospective application (and is thus useless verbiage).
This cannot be true.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
660 HAMDAN v. RUMSFELD
Scalia, J., dissenting
today) in which a jurisdiction-stripping provision was denied
immediate effect in pending cases, absent an explicit statu
tory reservation. By contrast, the cases granting such im
mediate effect are legion, and they repeatedly rely on the
plain language of the jurisdictional repeal as an “inflexible
trump,” ante, at 584, by requiring an express reservation to
save pending cases. See, e. g., Bruner, supra, at 115; Kline
v. Burke Constr. Co., 260 U. S. 226, 234 (1922); Hallowell,
239 U. S., at 508; Gwin v. United States, 184 U. S. 669, 675
(1902); Gurnee v. Patrick County, 137 U. S. 141, 144 (1890);
Sherman v. Grinnell, 123 U. S. 679, 680 (1887); Railroad Co.
v. Grant, supra, at 403, Assessors v. Osbornes, 9 Wall. 567,
575 (1870); Ex parte McCardle, 7 Wall., at 514; Ritchie,
supra, at 544; Norris v. Crocker, 13 How. 429, 440 (1852);
Yeaton v. United States, 5 Cranch 281 (1809) (Marshall, C. J.),
discussed in Gwin, supra, at 675; King v. Justices of the
Peace of London, 3 Burr. 1456, 1457, 97 Eng. Rep. 924, 925
(K. B. 1764). Cf. National Exchange Bank of Baltimore v.
Peters, 144 U. S. 570, 572 (1892).
B
Disregarding the plain meaning of § 1005(e)(1) and the re
quirement of explicit exception set forth in the foregoing
cases, the Court instead favors “a negative inference . . .
from the exclusion of language from one statutory provi
sion that is included in other provisions of the same stat
ute,” ante, at 578. Specifically, it appeals to the fact that
§ 1005(e)(2) and (e)(3) are explicitly made applicable to pend
ing cases (by § 1005(h)(2)). A negative inference of the sort
the Court relies upon might clarify the meaning of an am
biguous provision, but since the meaning of § 1005(e)(1) is
entirely clear, the omitted language in that context would
have been redundant.
Even if § 1005(e)(1) were at all ambiguous in its application
to pending cases, the “negative inference” from § 1005(h)(2)
touted by the Court would have no force. The numerous

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
661 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
cases in the Bruner line would at least create a powerful
default “presumption against jurisdiction,” ante, at 576.
The negative inference urged by the Court would be a partic
ularly awkward and indirect way of rebutting such a long
standing and consistent practice. This is especially true
since the negative inference that might be drawn from
§ 1005(h)(2)’s specification that certain provisions shall apply
to pending cases is matched by a negative inference in the
opposite direction that might be drawn from § 1005(b)(2),
which provides that certain provisions shall not apply to
pending cases.
The Court’s reliance on our opinion in Lindh v. Murphy,
521 U. S. 320 (1997), is utterly misplaced. Lindh involved
two provisions of the Antiterrorism and Effective Death
Penalty Act of 1996 (AEDPA): a set of amendments to chap
ter 153 of the federal habeas statute that redefined the scope
of collateral review by federal habeas courts; and a provision
creating a new chapter 154 in the habeas statute specially to
govern federal collateral review of state capital cases. See
521 U. S., at 326–327. The latter provision explicitly ren
dered the new chapter 154 applicable to cases pending at
the time of AEDPA’s enactment; the former made no specific
reference to pending cases. Id., at 327. In Lindh, we drew
a negative inference from chapter 154’s explicit reference to
pending cases, to conclude that the chapter 153 amendments
did not apply in pending cases. It was essential to our rea
soning, however, that both provisions appeared to be identi
cally difficult to classify under our retroactivity cases.
First, we noted that, after Landgraf, there was reason for
Congress to suppose that an explicit statement was required
to render the amendments to chapter 154 applicable in pend
ing cases, because the new chapter 154 “will have substan
tive as well as purely procedural effects.” 521 U. S., at 327.
The next step—and the critical step—in our reasoning was
that Congress had identical reason to suppose that an ex
plicit statement would be required to apply the chapter 153

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
662 HAMDAN v. RUMSFELD
Scalia, J., dissenting
amendments to pending cases, but did not provide it. Id.,
at 329. The negative inference of Lindh rested on the fact
that “[n]othing . . . but a different intent explain[ed] the dif
ferent treatment.” Ibid.
Here, by contrast, there is ample reason for the different
treatment. The exclusive-review provisions of the DTA, un
like both § 1005(e)(1) and the AEDPA amendments in Lindh,
confer new jurisdiction (in the D. C. Circuit) where there
was none before. For better or for worse, our recent
cases have contrasted jurisdiction-creating provisions with
jurisdiction-ousting provisions, retaining the venerable rule
that the latter are not retroactive even when applied in pend
ing cases, but strongly indicating that the former are typi
cally retroactive. For example, we stated in Hughes Air
craft Co. v. United States ex rel. Schumer, 520 U. S. 939, 951
(1997), that a statute that “creates jurisdiction where none
previously existed” is “as much subject to our presumption
against retroactivity as any other.” See also Republic of
Austria v. Altmann, 541 U. S. 677, 695 (2004) (opinion for the
Court by Stevens, J.); id., at 722 (Kennedy, J., dissenting).
The Court gives our retroactivity jurisprudence a dazzling
clarity in asserting that “subsections (e)(2) and (e)(3) ‘confer’
jurisdiction in a manner that cannot conceivably give rise
to retroactivity questions under our precedents.” 2 Ante, at
2 A comparison with Lindh v. Murphy, 521 U. S. 320 (1997), shows this
not to be true. Subsections (e)(2) and (e)(3) of § 1005 resemble the provi
sions of AEDPA at issue in Lindh (whose retroactivity as applied to pend
ing cases the Lindh majority did not rule upon, see id., at 326), in that
they “g[o] beyond ‘mere’ procedure,” id., at 327. They impose novel
and unprecedented disabilities on the Executive Branch in its conduct of
military affairs. Subsection (e)(2) imposes judicial review on the Combat
ant Status Review Tribunals (CSRTs), whose implementing order did not
subject them to review by Article III courts. See Memorandum from
Deputy Secretary of Defense Paul Wolfowitz re: Order Establishing Com
batant Status Review Tribunals, p. 3, § h (July 7, 2004), available at http://
www.defenselink.mil/news/Jul2004/d20040707review.pdf (all Internet ma

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
663 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
582. This statement rises to the level of sarcasm when one
considers its author’s description of the governing test of our
retroactivity jurisprudence:
“The conclusion that a particular rule operates ‘retroac
tively’ comes at the end of a process of judgment con
cerning the nature and extent of the change in the law
and the degree of connection between the operation of
the new rule and a relevant past event. Any test of
retroactivity will leave room for disagreement in hard
cases, and is unlikely to classify the enormous variety of
legal changes with perfect philosophical clarity. How
ever, retroactivity is a matter on which judges tend to
have ‘sound . . . instinct[s],’ . . . and familiar considera
tions of fair notice, reasonable reliance, and settled ex
pectations offer sound guidance.” Landgraf, 511 U. S.,
at 270 (opinion for the Court by Stevens, J.).
The only “familiar consideration,” “reasonable reliance,” and
“settled expectation” I am aware of pertaining to the present
terials as visited June 27, 2006, and available in Clerk of Court’s case file).
Subsection (e)(3) authorizes the D. C. Circuit to review “the validity of
any final decision rendered pursuant to Military Commission Order No. 1,”
§ 1005(e)(3)(A), 119 Stat. 2743. Historically, federal courts have never re
viewed the validity of the final decision of any military commission; their
jurisdiction has been restricted to considering the commission’s “lawful
authority to hear, decide and condemn,” In re Yamashita, 327 U. S. 1, 8
(1946) (emphasis added). See also Johnson v. Eisentrager, 339 U. S. 763,
786–787 (1950). Thus, contrary to the Court’s suggestion, ante, at 581,
582, subsections (e)(2) and (e)(3) confer new jurisdiction: They impose judi
cial oversight on a traditionally unreviewable exercise of military author
ity by the Commander in Chief. They arguably “spea[k] not just to the
power of a particular court but to . . . substantive rights . . . as well,”
Hughes Aircraft Co. v. United States ex rel. Schumer, 520 U. S. 939, 951
(1997)—namely, the unreviewable powers of the President. Our recent
cases had reiterated that the Executive is protected by the presumption
against retroactivity in such comparatively trivial contexts as suits for tax
refunds and increased pay, see Landgraf v. USI Film Products, 511 U. S.
244, 271, n. 25 (1994).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
664 HAMDAN v. RUMSFELD
Scalia, J., dissenting
case is the rule of Bruner—applicable to § 1005(e)(1), but not
to § 1005(e)(2) and (e)(3)—which the Court stubbornly disre
gards. It is utterly beyond question that § 1005(e)(2)’s and
(3)’s application to pending cases (without explicit specifica
tion) was not as clear as § 1005(e)(1)’s. That is alone enough
to explain the difference in treatment.
Another obvious reason for the specification was to stave
off any Suspension Clause problems raised by the immedi
ately effective ouster of jurisdiction brought about by sub
section (e)(1). That is to say, specification of the immediate
effectiveness of subsections (e)(2) and (e)(3) (which, unlike
subsection (e)(1), would not fall within the Bruner rule and
would not automatically be deemed applicable in pending
cases) could reasonably have been thought essential to be
sure of replacing the habeas jurisdiction that subsection
(e)(1) eliminated in pending cases with an adequate substi
tute. See infra, at 670–672.
These considerations by no means prove that an explicit
statement would be required to render subsections (e)(2) and
(e)(3) applicable in pending cases. But they surely gave
Congress ample reason to doubt that their application in
pending cases would unfold as naturally as the Court glibly
assumes. In any event, even if it were true that subsections
(e)(2) and (e)(3) “ ‘confer’ jurisdiction in a manner that cannot
conceivably give rise to retroactivity questions,” ante, at 582,
this would merely establish that subsection (h)(2)’s reference
to pending cases was wholly superfluous when applied to
subsections (e)(2) and (e)(3), just as it would have been for
subsection (e)(1). Lindh’s negative inference makes sense
only when Congress would have perceived “the wisdom of
being explicit” with respect to the immediate application of
both of two statutory provisions, 521 U. S., at 328, but chose
to be explicit only for one of them—not when it would have
perceived no need to be explicit for both, but enacted a re
dundancy only for one.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
665 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
In short, it is simply untrue that Congress “ ‘should have
been just as concerned about’ ” specifying the application of
§ 1005(e)(1) to pending cases, ante, at 578 (quoting Lindh,
supra, at 329). In fact, the negative-inference approach of
Lindh is particularly inappropriate in this case, because the
negative inference from § 1005(h)(2) would tend to defeat the
purpose of the very provisions that are explicitly rendered
applicable in pending cases, § 1005(e)(2) and (3). Those pro
visions purport to vest “exclusive” jurisdiction in the D. C.
Circuit to consider the claims raised by petitioner here. See
infra, at 670–672. By drawing a negative inference a` la
Lindh, the Court supplants this exclusive-review mechanism
with a dual-review mechanism for petitioners who were ex
peditious enough to file applications challenging the CSRTs
or military commissions before December 30, 2005. What
ever the force of Lindh’s negative inference in other cases,
it surely should not apply here to defeat the purpose of the
very provision from which the negative inference is drawn.
C
Worst of all is the Court’s reliance on the legislative his
tory of the DTA to buttress its implausible reading of
§ 1005(e)(1). We have repeatedly held that such reliance is
impermissible where, as here, the statutory language is un
ambiguous. But the Court nevertheless relies both on floor
statements from the Senate and (quite heavily) on the draft
ing history of the DTA. To begin with floor statements: The
Court urges that some “statements made by Senators pre
ceding passage of the Act lend further support to” the
Court’s interpretation, citing excerpts from the floor debate
that support its view, ante, at 580, n. 10. The Court im
mediately goes on to discount numerous floor statements by
the DTA’s sponsors that flatly contradict its view, because
“those statements appear to have been inserted into the
Congressional Record after the Senate debate.” Ibid. Of
course this observation, even if true, makes no difference

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
666 HAMDAN v. RUMSFELD
Scalia, J., dissenting
unless one indulges the fantasy that Senate floor speeches
are attended (like the Philippics of Demosthenes) by throngs
of eager listeners, instead of being delivered (like Demosthe
nes’ practice sessions on the beach) alone into a vast empti
ness. Whether the floor statements are spoken where no
Senator hears, or written where no Senator reads, they rep
resent at most the views of a single Senator. In any event,
the Court greatly exaggerates the one-sidedness of the por
tions of the floor debate that clearly occurred before the
DTA’s enactment. Some of the statements of Senator Gra
ham, a sponsor of the bill, only make sense on the assumption
that pending cases are covered.3 And at least one opponent
of the DTA unmistakably expressed his understanding that
it would terminate our jurisdiction in this very case.4 (Of
course in its discussion of legislative history the Court
wholly ignores the President’s signing statement, which ex
plicitly set forth his understanding that the DTA ousted ju
risdiction over pending cases.5)
3 “Because I have described how outrageous these claims are—about the
exercise regime, the reading materials—most Americans would be highly
offended to know that terrorists are suing us in our own courts about what
they read.” 151 Cong. Rec. S12756 (Nov. 14, 2005). “Instead of having
unlimited habeas corpus opportunities under the Constitution, we give
every enemy combatant, all 500, a chance to go to Federal court, the Cir
cuit Court of Appeals for the District of Columbia. . . . It will be a one-time
deal.” Id., at S12754. “This Levin-Graham-Kyl amendment allows
every detainee under our control to have their day in court. They are
allowed to appeal their convictions.” Id., at S12801 (Nov. 15, 2005); see
also id., at S12799 (rejecting the notion that “an enemy combatant terror
ist al-Qaida member should be able to have access to our Federal courts
under habeas like an American citizen”).
4 “An earlier part of the amendment provides that no court, justice, or
judge shall have jurisdiction to consider the application for writ of habeas
corpus. . . . Under the language of exclusive jurisdiction in the DC Circuit,
the U. S. Supreme Court would not have jurisdiction to hear the Hamdan
case . . . .” Id., at S12796 (statement of Sen. Specter).
5 “[T]he executive branch shall construe section 1005 to preclude the
Federal courts from exercising subject matter jurisdiction over any exist
ing or future action, including applications for writs of habeas corpus, de

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
667 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
But selectivity is not the greatest vice in the Court’s use
of floor statements to resolve today’s case. These state
ments were made when Members of Congress were fully
aware that our continuing jurisdiction over this very case
was at issue. The question was divisive, and floor state
ments made on both sides were undoubtedly opportunistic
and crafted solely for use in the briefs in this very litigation.
See, e. g., 151 Cong. Rec. S14257–S14258 (Dec. 21, 2005)
(statement of Sen. Levin) (arguing against a reading that
would “stri[p] the Federal courts of jurisdiction to consider
pending cases, including the Hamdan case now pending in
the Supreme Court,” and urging that Lindh requires the
same negative inference that the Court indulges today (em
phasis added)). The Court’s reliance on such statements
cannot avoid the appearance of similar opportunism. In a
virtually identical context, the author of today’s opinion has
written for the Court that “[t]he legislative history discloses
some frankly partisan statements about the meaning of the
final effective date language, but those statements cannot
plausibly be read as reflecting any general agreement.”
Landgraf, 511 U. S., at 262 (opinion for the Court by Ste
vens, J.). Likewise, the handful of floor statements that the
Court treats as authoritative do not “reflec[t] any general
agreement.” They reflect the now-common tactic—which
the Court once again rewards—of pursuing through floor
speech ipse dixit what could not be achieved through the
constitutionally prescribed method of putting language into
a bill that a majority of both Houses vote for and the Presi
dent signs.
With regard to the floor statements, at least the Court
shows some semblance of seemly shame, tucking away its
scribed in section 1005.” President’s Statement on Signing of H. R. 2863,
the “Department of Defense, Emergency Supplemental Appropriations
to Address Hurricanes in the Gulf of Mexico, and Pandemic Influenza
Act, 2006” (Dec. 30, 2005), available at http://www.whitehouse.gov/news/
releases/2005/12/print/20051230-8.html.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
668 HAMDAN v. RUMSFELD
Scalia, J., dissenting
reference to them in a halfhearted footnote. Not so for its
reliance on the DTA’s drafting history, which is displayed
prominently, see ante, at 579–580. I have explained else
where that such drafting history is no more legitimate or
reliable an indicator of the objective meaning of a statute
than any other form of legislative history. This case pre
sents a textbook example of its unreliability. The Court,
ante, at 579, trumpets the fact that a bill considered in the
Senate included redundant language, not included in the
DTA as passed, reconfirming that the abolition of habeas ju
risdiction “shall apply to any application or other action that
is pending on or after the date of the enactment of this Act.”
151 Cong. Rec. S12655 (Nov. 10, 2005). But this earlier ver
sion of the bill also differed from the DTA in other material
respects. Most notably, it provided for postdecision review
by the D. C. Circuit only of the decisions of CSRTs, not mili
tary commissions, ibid.; and it limited that review to whether
“the status determination . . . was consistent with the proce
dures and standards specified by the Secretary of Defense,”
ibid., not whether “the use of such standards and procedures
. . . is consistent with the Constitution and laws of the United
States,” DTA § 1005(e)(2)(C)(ii), 119 Stat. 2742. To say that
what moved Senators to reject this earlier bill was the “ac
tion that is pending” provision surpasses the intuitive pow
ers of even this Court’s greatest Justices.6 And to think
that the House and the President also had this rejection
firmly in mind is absurd. As always—but especially in the
context of strident, partisan legislative conflict of the sort
that characterized enactment of this legislation—the lan
guage of the statute that was actually passed by both Houses
of Congress and signed by the President is our only authori
tative and only reliable guidepost.
6 The Court asserts that “it cannot be said that the changes to subsection
(h)(2) were inconsequential,” ante, at 580, n. 10, but the Court’s sole evi
dence is the self-serving floor statements that it selectively cites.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
669 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
D
A final but powerful indication of the fact that the Court
has made a mess of this statute is the nature of the conse
quences that ensue. Though this case concerns a habeas ap
plication challenging a trial by military commission, DTA
§ 1005(e)(1) strips the courts of jurisdiction to hear or con
sider any “application for a writ of habeas corpus filed by or
on behalf of an alien detained by the Department of Defense
at Guantanamo Bay, Cuba.” The vast majority of pending
petitions, no doubt, do not relate to military commissions at
all, but to more commonly challenged aspects of “detention”
such as the terms and conditions of confinement. See Rasul
v. Bush, 542 U. S. 466, 498 (2004) (Scalia, J., dissenting).
The Solicitor General represents that “[h]abeas petitions
have been filed on behalf of a purported 600 [Guantanamo
Bay] detainees,” including one that “seek[s] relief on behalf
of every Guantanamo detainee who has not already filed an
action,” Respondents’ Motion to Dismiss for Lack of Jurisdic
tion 20, n. 10 (hereinafter Motion to Dismiss). The Court’s
interpretation transforms a provision abolishing jurisdiction
over all Guantanamo-related habeas petitions into a provi
sion that retains jurisdiction over cases sufficiently numer
ous to keep the courts busy for years to come.
II
Because I would hold that § 1005(e)(1) unambiguously ter
minates the jurisdiction of all courts to “hear or consider”
pending habeas applications, I must confront petitioner’s ar
guments that the provision, so interpreted, violates the Sus
pension Clause. This claim is easily dispatched. We stated
in Johnson v. Eisentrager, 339 U. S. 763, 768 (1950):
“We are cited to no instance where a court, in this or
any other country where the writ is known, has issued
it on behalf of an alien enemy who, at no relevant time
and in no stage of his captivity, has been within its terri
torial jurisdiction. Nothing in the text of the Constitu

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
670 HAMDAN v. RUMSFELD
Scalia, J., dissenting
tion extends such a right, nor does anything in our
statutes.”
Notwithstanding the ill-considered dicta in the Court’s opin
ion in Rasul, 542 U. S., at 480–481, it is clear that Guantan
amo Bay, Cuba, is outside the sovereign “territorial jurisdic
tion” of the United States. See id., at 500–505 (Scalia, J.,
dissenting). Petitioner, an enemy alien detained abroad, has
no rights under the Suspension Clause.
But even if petitioner were fully protected by the Clause,
the DTA would create no suspension problem. This Court
has repeatedly acknowledged that “the substitution of a col
lateral remedy which is neither inadequate nor ineffective to
test the legality of a person’s detention does not constitute a
suspension of the writ of habeas corpus.” Swain v. Press
ley, 430 U. S. 372, 381 (1977); see also INS v. St. Cyr, 533
U. S. 289, 314, n. 38 (2001) (“Congress could, without raising
any constitutional questions, provide an adequate substitute
through the courts of appeals”).
Petitioner has made no showing that the postdecision ex
clusive review by the D. C. Circuit provided in § 1005(e)(3)
is inadequate to test the legality of his trial by military
commission. His principal argument is that the exclusive
review provisions are inadequate because they foreclose re
view of the claims he raises here. Though petitioner’s brief
does not parse the statutory language, his argument evi
dently rests on an erroneously narrow reading of DTA
§ 1005(e)(3)(D)(ii), 119 Stat. 2743. That provision grants the
D. C. Circuit authority to review, “to the extent the Constitu
tion and laws of the United States are applicable, whether
the use of such standards and procedures to reach the final
decision is consistent with the Constitution and laws of the
United States.” In the quoted text, the phrase “such stand
ards and procedures” refers to “the standards and proce
dures specified in the military order referred to in subpara
graph (A),” namely, “Military Commission Order No. 1, dated
August 31, 2005 (or any successor military order).” DTA

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
671 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
§ 1005(e)(3)(D)(i), (e)(3)(A), ibid. This Military Commission
Order (Order No. 1) is the Department of Defense’s funda
mental implementing order for the President’s order author
izing trials by military commission. Order No. 1 establishes
commissions, § 2; delineates their jurisdiction, § 3; provides
for their officers, § 4(A); provides for their prosecution and
defense counsel, § 4(B), (C); lays out all their procedures, both
pretrial and trial, § 5(A)–(P), § 6(A)–(G); and provides for
post-trial military review through the Secretary of Defense
and the President, § 6(H). In short, the “standards and pro
cedures specified in” Order No. 1 include every aspect of the
military commissions, including the fact of their existence
and every respect in which they differ from courts-martial.
Petitioner’s claims that the President lacks legal authority
to try him before a military commission constitute claims
that “the use of such standards and procedures,” as specified
in Order No. 1, is “[in]consistent with the Constitution and
laws of the United States,” DTA § 1005(e)(3)(D)(ii), 119 Stat.
2743. The D. C. Circuit thus retains jurisdiction to consider
these claims on postdecision review, and the Government
does not dispute that the DTA leaves unaffected our certio
rari jurisdiction under 28 U. S. C. § 1254(1) to review the
D. C. Circuit’s decisions. Motion to Dismiss 16, n. 8. Thus,
the DTA merely defers our jurisdiction to consider petition
er’s claims; it does not eliminate that jurisdiction. It consti
tutes neither an “inadequate” nor an “ineffective” substitute
for petitioner’s pending habeas application.7
7 Petitioner also urges that he could be subject to indefinite delay if
military officials and the President are deliberately dilatory in reviewing
the decision of his commission. In reviewing the constitutionality of leg
islation, we generally presume that the Executive will implement its pro
visions in good faith. And it is unclear in any event that delay would
inflict any injury on petitioner, who (after an adverse determination by
his CSRT, see 344 F. Supp. 2d 152, 161 (DC 2004)) is already subject to
indefinite detention under our decision in Hamdi v. Rumsfeld, 542 U. S.
507 (2004) (plurality opinion). Moreover, the mere possibility of delay
does not render an alternative remedy “inadequate [o]r ineffective to test

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
672 HAMDAN v. RUMSFELD
Scalia, J., dissenting
Though it does not squarely address the issue, the Court
hints ominously that “the Government’s preferred reading”
would “rais[e] grave questions about Congress’ authority to
impinge upon this Court’s appellate jurisdiction, particularly
in habeas cases.” Ante, at 575 (citing Ex parte Yerger, 8
Wall. 85 (1869); Felker v. Turpin, 518 U. S. 651 (1996); Dur
ousseau v. United States, 6 Cranch 307 (1810); United States
v. Klein, 13 Wall. 128 (1872); and Ex parte McCardle, 7 Wall.
506). It is not clear how there could be any such lurking
questions, in light of the aptly named “Exceptions Clause”
of Article III, § 2, which, in making our appellate jurisdiction
subject to “such Exceptions, and under such Regulations as
the Congress shall make,” explicitly permits exactly what
Congress has done here. But any doubt our prior cases
might have created on this score is surely chimerical in this
case. As just noted, the exclusive-review provisions pro
vide a substitute for habeas review adequate to satisfy the
Suspension Clause, which forbids the suspension of the writ
of habeas corpus. A fortiori they provide a substitute ade
quate to satisfy any implied substantive limitations, whether
real or imaginary, upon the Exceptions Clause, which au
thorizes such exceptions as § 1005(e)(1).
III
Even if Congress had not clearly and constitutionally elim
inated jurisdiction over this case, neither this Court nor the
lower courts ought to exercise it. Traditionally, equitable
principles govern both the exercise of habeas jurisdiction
and the granting of the injunctive relief sought by petitioner.
See Schlesinger v. Councilman, 420 U. S. 738, 754 (1975);
the legality” of a military commission trial. Swain v. Pressley, 430 U. S.
372, 381 (1977). In an analogous context, we discounted the notion that
postponement of relief until postconviction review inflicted any cognizable
injury on a serviceman charged before a military court-martial. Schle
singer v. Councilman, 420 U. S. 738, 754–755 (1975); see also Younger v.
Harris, 401 U. S. 37, 46 (1971).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
673 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
Weinberger v. Romero-Barcelo, 456 U. S. 305, 311 (1982). In
light of Congress’s provision of an alternate avenue for peti
tioner’s claims in § 1005(e)(3), those equitable principles coun
sel that we abstain from exercising jurisdiction in this case.
In requesting abstention, the Government relies princi
pally on Councilman, in which we abstained from consid
ering a serviceman’s claim that his charge for marijuana
possession was not sufficiently “service-connected” to trig
ger the subject-matter jurisdiction of the military courts
martial. See 420 U. S., at 740, 758. Admittedly, Coun
cilman does not squarely control petitioner’s case, but it
provides the closest analogue in our jurisprudence. As the
Court describes, ante, at 586, Councilman “identifie[d] two
considerations of comity that together favor[ed] abstention
pending completion of ongoing court-martial proceedings
against service personnel.” But the Court errs in finding
these considerations inapplicable to this case. Both of them,
and a third consideration not emphasized in Councilman, all
cut in favor of abstention here.
First, the Court observes that Councilman rested in part
on the fact that “military discipline and, therefore, the effi
cient operation of the Armed Forces are best served if the
military justice system acts without regular interference
from civilian courts,” and concludes that “Hamdan is not a
member of our Nation’s Armed Forces, so concerns about
military discipline do not apply.” Ante, at 586, 587. This is
true enough. But for some reason, the Court fails to make
any inquiry into whether military commission trials might
involve other “military necessities” or “unique military exi
gencies,” 420 U. S., at 757, comparable in gravity to those at
stake in Councilman. To put this in context: The charge
against the respondent in Councilman was the off-base pos
session and sale of marijuana while he was stationed in Fort
Sill, Oklahoma, see id., at 739–740. The charge against the
petitioner here is joining and actively abetting the murder
ous conspiracy that slaughtered thousands of innocent Amer

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
674 HAMDAN v. RUMSFELD
Scalia, J., dissenting
ican civilians without warning on September 11, 2001.
While Councilman held that the prosecution of the former
charge involved “military necessities” counseling against our
interference, the Court does not even ponder the same ques
tion for the latter charge.
The reason for the Court’s “blinkered study” of this ques
tion, ante, at 584, is not hard to fathom. The principal opin
ion on the merits makes clear that it does not believe that
the trials by military commission involve any “military ne
cessity” at all: “The charge’s shortcomings . . . are indicative
of a broader inability on the Executive’s part here to satisfy
the most basic precondition . . . for establishment of military
commissions: military necessity.” Ante, at 612. This is
quite at odds with the views on this subject expressed by our
political branches. Because of “military necessity,” a joint
session of Congress authorized the President to “use all nec
essary and appropriate force,” including military commis
sions, “against those nations, organizations, or persons [such
as petitioner] he determines planned, authorized, committed,
or aided the terrorist attacks that occurred on September 11,
2001.” Authorization for Use of Military Force, § 2(a), 115
Stat. 224, note following 50 U. S. C. § 1541 (2000 ed., Supp.
III). In keeping with this authority, the President has de
termined that “[t]o protect the United States and its citizens,
and for the effective conduct of military operations and pre
vention of terrorist attacks, it is necessary for individuals
subject to this order . . . to be detained, and, when tried, to
be tried for violations of the laws of war and other applicable
laws by military tribunals.” Military Order of Nov. 13, 2001,
3 CFR, 2001 Comp., § 1(e), p. 918 (2002) (hereinafter Military
Order). It is not clear where the Court derives the author
ity—or the audacity—to contradict this determination. If
“military necessities” relating to “duty” and “discipline” re
quired abstention in Councilman, supra, at 757, military ne
cessities relating to the disabling, deterrence, and punish

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
675 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
ment of the mass-murdering terrorists of September 11
require abstention all the more here.
The Court further seeks to distinguish Councilman on the
ground that “the tribunal convened to try Hamdan is not
part of the integrated system of military courts, complete
with independent review panels, that Congress has estab
lished.” Ante, at 587. To be sure, Councilman emphasized
that “Congress created an integrated system of military
courts and review procedures, a critical element of which is
the Court of Military Appeals consisting of civilian judges
completely removed from all military influence or persua
sion, who would gain over time thorough familiarity with
military problems.” 420 U. S., at 758 (internal quotation
marks and footnote omitted). The Court contrasts this “in
tegrated system” insulated from military influence with the
review scheme established by Order No. 1, which “provides
that appeal of a review panel’s decision may be had only to
the Secretary himself, § 6(H)(5), and then, finally, to the Pres
ident, § 6(H)(6).” Ante, at 587.
Even if we were to accept the Court’s extraordinary as
sumption that the President “lack[s] the structural insulation
from military influence that characterizes the Court of Ap
peals for the Armed Forces,” ante, at 587–588,8 the Court’s
description of the review scheme here is anachronistic. As
of December 30, 2005, the “fina[l]” review of decisions by
military commissions is now conducted by the D. C. Circuit
pursuant to § 1005(e)(3) of the DTA, and by this Court under
28 U. S. C. § 1254(1). This provision for review by Article
III courts creates, if anything, a review scheme more insu
8 The very purpose of Article II’s creation of a civilian Commander in
Chief in the President of the United States was to generate “structural
insulation from military influence.” See The Federalist No. 28 (A. Hamil
ton); id., No. 69 (same). We do not live under a military junta. It is a
disservice to both those in the Armed Forces and the President to suggest
that the President is subject to the undue control of the military.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
676 HAMDAN v. RUMSFELD
Scalia, J., dissenting
lated from executive control than that in Councilman.9 At
the time we decided Councilman, Congress had not “con
ferred on any Art[icle] III court jurisdiction directly to re
view court-martial determinations.” 420 U. S., at 746. The
final arbiter of direct appeals was the Court of Military Ap
peals (now the Court of Appeals for the Armed Forces), an
Article I court whose members possessed neither life tenure,
nor salary protection, nor the constitutional protection from
removal provided to federal judges in Article III, § 1. See
10 U. S. C. § 867(a)(2) (1970 ed.).
Moreover, a third consideration counsels strongly in favor
of abstention in this case. Councilman reasoned that the
“considerations of comity, the necessity of respect for coor
dinate judicial systems” that motivated our decision in
Younger v. Harris, 401 U. S. 37 (1971), were inapplicable to
courts-martial, because “the peculiar demands of federalism
are not implicated.” 420 U. S., at 756, 757. Though mili
tary commissions likewise do not implicate “the peculiar de
mands of federalism,” considerations of interbranch comity
9 In rejecting our analysis, the Court observes that appeals to the D. C.
Circuit under subsection (e)(3) are discretionary, rather than as of right,
when the military commission imposes a sentence less than 10 years’ im
prisonment, see ante, at 588, n. 19, 616; § 1005(e)(3)(B), 119 Stat. 2743.
The relevance of this observation to the abstention question is unfathom
able. The fact that Article III review is discretionary does not mean that
it lacks “structural insulation from military influence,” ante, at 587, and
its discretionary nature presents no obstacle to the courts’ future review
of these cases.
The Court might more cogently have relied on the discretionary nature
of review to argue that the statute provides an inadequate substitute for
habeas review under the Suspension Clause. See supra, at 670–672.
But this argument would have no force, even if all appeals to the D. C.
Circuit were discretionary. The exercise of habeas jurisdiction has tradi
tionally been entirely a matter of the court’s equitable discretion, see
Withrow v. Williams, 507 U. S. 680, 715–718 (1993) (Scalia, J., concurring
in part and dissenting in part), so the fact that habeas jurisdiction is re
placed by discretionary appellate review does not render the substitution
“inadequate.” Swain, 430 U. S., at 381.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
677 Cite as: 548 U. S. 557 (2006)
Scalia, J., dissenting
at the federal level weigh heavily against our exercise of eq
uity jurisdiction in this case. Here, apparently for the first
time in history, see Motion to Dismiss 6, a District Court
enjoined ongoing military commission proceedings, which
had been deemed “necessary” by the President “[t]o protect
the United States and its citizens, and for the effective con
duct of military operations and prevention of terrorist at
tacks.” Military Order § 1(e). Such an order brings the Ju
dicial Branch into direct conflict with the Executive in an
area where the Executive’s competence is maximal and ours
is virtually nonexistent. We should exercise our equitable
discretion to avoid such conflict. Instead, the Court rushes
headlong to meet it. Elsewhere, we have deferred exercis
ing habeas jurisdiction until state courts have “the first op
portunity to review” a petitioner’s claim, merely to “reduc[e]
friction between the state and federal court systems.”
O’Sullivan v. Boerckel, 526 U. S. 838, 844, 845 (1999). The
“friction” created today between this Court and the Execu
tive Branch is many times more serious.
In the face of such concerns, the Court relies heavily on
Ex parte Quirin, 317 U. S. 1 (1942): “Far from abstaining
pending the conclusion of military proceedings, which were
ongoing, [in Quirin] we convened a special Term to hear the
case and expedited our review.” Ante, at 588. It is likely
that the Government in Quirin, unlike here, preferred a
hasty resolution of the case in this Court, so that it could
swiftly execute the sentences imposed, see Hamdi v. Rums
feld, 542 U. S. 507, 569 (2004) (Scalia, J., dissenting). But
the Court’s reliance on Quirin suffers from a more funda
mental defect: Once again, it ignores the DTA, which creates
an avenue for the consideration of petitioner’s claims that did
not exist at the time of Quirin. Collateral application for
habeas review was the only vehicle available. And there
was no compelling reason to postpone consideration of the
Quirin application until the termination of military proceed
ings, because the only cognizable claims presented were gen

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
678 HAMDAN v. RUMSFELD
Thomas, J., dissenting
eral challenges to the authority of the commissions that
would not be affected by the specific proceedings. See
supra, at 662–663, n. 2. In the DTA, by contrast, Congress
has expanded the scope of Article III review and has chan
neled it exclusively through a single, postverdict appeal to
Article III courts. Because Congress has created a novel
unitary scheme of Article III review of military commissions
that was absent in 1942, Quirin is no longer governing
precedent.
I would abstain from exercising our equity jurisdiction, as
the Government requests.
* * *
For the foregoing reasons, I dissent.
Justice Thomas, with whom Justice Scalia joins, and
with whom Justice Alito joins in all but Parts I, II–C–1,
and III–B–2, dissenting.
For the reasons set forth in Justice Scalia’s dissent, it is
clear that this Court lacks jurisdiction to entertain petition
er’s claims, see ante, at 655–669. The Court having con
cluded otherwise, it is appropriate to respond to the Court’s
resolution of the merits of petitioner’s claims because its
opinion openly flouts our well-established duty to respect the
Executive’s judgment in matters of military operations and
foreign affairs. The plurality’s evident belief that it is quali
fied to pass on the “military necessity,” ante, at 612, of the
Commander in Chief ’s decision to employ a particular form
of force against our enemies is so antithetical to our constitu
tional structure that it simply cannot go unanswered. I re
spectfully dissent.
I
Our review of petitioner’s claims arises in the context of
the President’s wartime exercise of his Commander in Chief
authority in conjunction with the complete support of Con
gress. Accordingly, it is important to take measure of the

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
679 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
respective roles the Constitution assigns to the three
branches of our Government in the conduct of war.
As I explained in Hamdi v. Rumsfeld, 542 U. S. 507 (2004),
the structural advantages attendant to the Executive
Branch—namely, the decisiveness, “ ‘activity, secrecy, and
dispatch’ ” that flow from the Executive’s “ ‘unity,’ ” id., at
581 (dissenting opinion) (quoting The Federalist No. 70, p. 472
(J. Cooke ed. 1961) (A. Hamilton))—led the Founders to con
clude that the “President ha[s] primary responsibility—along
with the necessary power—to protect the national security
and to conduct the Nation’s foreign relations.” 542 U. S., at
580. Consistent with this conclusion, the Constitution vests
in the President “[t]he executive Power,” Art. II, § 1, pro
vides that he “shall be Commander in Chief ” of the Armed
Forces, § 2, and places in him the power to recognize foreign
governments, § 3. This Court has observed that these pro
visions confer upon the President broad constitutional au
thority to protect the Nation’s security in the manner he
deems fit. See, e. g., Prize Cases, 2 Black 635, 668 (1863) (“If
a war be made by invasion of a foreign nation, the President
is not only authorized but bound to resist force by force . . .
without waiting for any special legislative authority”); Flem
ing v. Page, 9 How. 603, 615 (1850) (acknowledging that the
President has the authority to “employ [the Nation’s Armed
Forces] in the manner he may deem most effectual to harass
and conquer and subdue the enemy”).
Congress, to be sure, has a substantial and essential role
in both foreign affairs and national security. But “Congress
cannot anticipate and legislate with regard to every possible
action the President may find it necessary to take or every
possible situation in which he might act,” and “[s]uch failure
of Congress . . . does not, ‘especially . . . in the areas of
foreign policy and national security,’ imply ‘congressional
disapproval’ of action taken by the Executive.” Dames &
Moore v. Regan, 453 U. S. 654, 678 (1981) (quoting Haig v.
Agee, 453 U. S. 280, 291 (1981)). Rather, in these domains,

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
680 HAMDAN v. RUMSFELD
Thomas, J., dissenting
the fact that Congress has provided the President with broad
authorities does not imply—and the Judicial Branch should
not infer—that Congress intended to deprive him of par
ticular powers not specifically enumerated. See Dames &
Moore, 453 U. S., at 678 (“[T]he enactment of legislation
closely related to the question of the President’s authority in
a particular case which evinces legislative intent to accord
the President broad discretion may be considered to invite
measures on independent presidential responsibility” (inter
nal quotation marks omitted)).
When “the President acts pursuant to an express or im
plied authorization from Congress,” his actions are “ ‘sup
ported by the strongest of presumptions and the widest
latitude of judicial interpretation, and the burden of
persuasion . . . rest[s] heavily upon any who might attack
it.’ ” Id., at 668 (quoting Youngstown Sheet & Tube Co. v.
Sawyer, 343 U. S. 579, 637 (1952) (Jackson, J., concurring)).
Accordingly, in the very context that we address today, this
Court has concluded that “the detention and trial of petition
ers—ordered by the President in the declared exercise of his
powers as Commander in Chief of the Army in time of war
and of grave public danger—are not to be set aside by the
courts without the clear conviction that they are in conflict
with the Constitution or laws of Congress constitutionally
enacted.” Ex parte Quirin, 317 U. S. 1, 25 (1942).
Under this framework, the President’s decision to try
Hamdan before a military commission for his involvement
with al Qaeda is entitled to a heavy measure of deference.
In the present conflict, Congress has authorized the Presi
dent “to use all necessary and appropriate force against
those nations, organizations, or persons he determines
planned, authorized, committed, or aided the terrorist at
tacks that occurred on September 11, 2001 . . . in order to
prevent any future acts of international terrorism against
the United States by such nations, organizations or persons.”
Authorization for Use of Military Force (AUMF), 115 Stat.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
681 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
224, note following 50 U. S. C. § 1541 (2000 ed., Supp. III)
(emphasis added). As a plurality of the Court observed in
Hamdi, the “capture, detention, and trial of unlawful com
batants, by ‘universal agreement and practice,’ are ‘impor
tant incident[s] of war,’ ” 542 U. S., at 518 (quoting Quirin,
supra, at 28, 30; emphasis added), and are therefore “an exer
cise of the ‘necessary and appropriate force’ Congress has
authorized the President to use,” Hamdi, 542 U. S., at 518;
id., at 587 (Thomas, J., dissenting). Hamdi’s observation
that military commissions are included within the AUMF’s
authorization is supported by this Court’s previous recogni
tion that “[a]n important incident to the conduct of war is
the adoption of measures by the military commander, not
only to repel and defeat the enemy, but to seize and subject
to disciplinary measures those enemies who, in their attempt
to thwart or impede our military effort, have violated the
law of war.” In re Yamashita, 327 U. S. 1, 11 (1946); see
also Quirin, supra, at 28–29; Madsen v. Kinsella, 343 U. S.
341, 354, n. 20 (1952) (“ ‘[T]he military commission . . . is an
institution of the greatest importance in a period of war and
should be preserved’ ” (quoting S. Rep. No. 229, 63d Cong.,
2d Sess., 53 (1914) (testimony of Gen. Crowder))).
Although the Court concedes the legitimacy of the Presi
dent’s use of military commissions in certain circumstances,
ante, at 594, it suggests that the AUMF has no bearing on
the scope of the President’s power to utilize military commis
sions in the present conflict, ibid. Instead, the Court deter
mines the scope of this power based exclusively on Article
21 of the Uniform Code of Military Justice (UCMJ), 10
U. S. C. § 821, the successor to Article 15 of the Articles of
War, which Quirin held “authorized trial of offenses against
the law of war before [military] commissions.” 317 U. S.,
at 29. As I shall discuss below, Article 21 alone supports
the use of commissions here. Nothing in the language of
Article 21, however, suggests that it outlines the entire reach
of congressional authorization of military commissions in all

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
682 HAMDAN v. RUMSFELD
Thomas, J., dissenting
conflicts—quite the contrary, the language of Article 21 pre
supposes the existence of military commissions under an in
dependent basis of authorization.1 Indeed, consistent with
Hamdi’s conclusion that the AUMF itself authorizes the trial
of unlawful combatants, the original sanction for military
commissions historically derived from congressional authori
zation of “the initiation of war” with its attendant authoriza
tion of “the employment of all necessary and proper agencies
for its due prosecution.” W. Winthrop, Military Law and
Precedents 831 (rev. 2d ed. 1920) (hereinafter Winthrop) (em
phasis deleted). Accordingly, congressional authorization
for military commissions pertaining to the instant conflict
derives not only from Article 21 of the UCMJ, but also from
the more recent, and broader, authorization contained in
the AUMF.2
I note the Court’s error respecting the AUMF not because
it is necessary to my resolution of this case—Hamdan’s mili
tary commission can plainly be sustained solely under Article
21—but to emphasize the complete congressional sanction of
the President’s exercise of his Commander in Chief authority
to conduct the present war. In such circumstances, as pre
viously noted, our duty to defer to the Executive’s military
and foreign policy judgment is at its zenith; it does not coun
1 As previously noted, Article 15 of the Articles of War was the prede
cessor of Article 21 of the UCMJ. Article 21 provides as follows: “The
provisions of this chapter conferring jurisdiction upon courts-martial do
not deprive military commissions, provost courts, or other military tribu
nals of concurrent jurisdiction with respect to offenders or offenses that
by statute or by the law of war may be tried by military commissions,
provost courts, or other military tribunals.” 10 U. S. C. § 821.
2 Although the President very well may have inherent authority to try
unlawful combatants for violations of the law of war before military com
missions, we need not decide that question because Congress has author
ized the President to do so. Cf. Hamdi v. Rumsfeld, 542 U. S. 507, 587
(2004) (Thomas, J., dissenting) (same conclusion respecting detention of
unlawful combatants).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
683 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
tenance the kind of second-guessing the Court repeatedly
engages in today. Military and foreign policy judgments
“ ‘are and should be undertaken only by those directly
responsible to the people whose welfare they advance
or imperil. They are decisions of a kind for which the
Judiciary has neither aptitude, facilities nor responsibil
ity and which has long been held to belong in the domain
of political power not subject to judicial intrusion or in
quiry.’ ” Hamdi, supra, at 582–583 (Thomas, J., dis
senting) (quoting Chicago & Southern Air Lines, Inc. v.
Waterman S. S. Corp., 333 U. S. 103, 111 (1948)).
It is within this framework that the lawfulness of Hamdan’s
commission should be examined.
II
The plurality accurately describes some aspects of the his
tory of military commissions and the prerequisites for their
use. Thus, I do not dispute that military commissions have
historically been “used in three [different] situations,” ante,
at 595, and that the only situation relevant to the instant
case is the use of military commissions “ ‘to seize and subject
to disciplinary measures those enemies who . . . have violated
the law of war,’ ” ante, at 596 (quoting Quirin, supra, at 28–
29). Similarly, I agree with the plurality that Winthrop’s
treatise sets forth the four relevant considerations for deter
mining the scope of a military commission’s jurisdiction, con
siderations relating to the (1) time and (2) place of the of
fense, (3) the status of the offender, and (4) the nature of the
offense charged. Winthrop 836–840. The Executive has
easily satisfied these considerations here. The plurality’s
contrary conclusion rests upon an incomplete accounting and
an unfaithful application of those considerations.
A
The first two considerations are that a law-of-war military
commission may only assume jurisdiction of “offences com

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
684 HAMDAN v. RUMSFELD
Thomas, J., dissenting
mitted within the field of the command of the convening com
mander,” and that such offenses “must have been committed
within the period of the war.” See id., at 836, 837; ante,
at 597. Here, as evidenced by Hamdan’s charging document,
the Executive has determined that the theater of the present
conflict includes “Afghanistan, Pakistan and other countries”
where al Qaeda has established training camps, App. to Pet.
for Cert. 64a, and that the duration of that conflict dates back
(at least) to Usama bin Laden’s August 1996 Declaration of
Jihad Against the Americans, ibid. Under the Executive’s
description of the conflict, then, every aspect of the charge,
which alleges overt acts in “Afghanistan, Pakistan, Yemen
and other countries” taking place from 1996 to 2001, satisfies
the temporal and geographic prerequisites for the exercise
of law-of-war military commission jurisdiction. Id., at 65a–
67a. And these judgments pertaining to the scope of the
theater and duration of the present conflict are committed
solely to the President in the exercise of his Commander in
Chief authority. See Prize Cases, 2 Black, at 670 (conclud
ing that the President’s Commander in Chief judgment about
the nature of a particular conflict was “a question to be de
cided by him, and this Court must be governed by the deci
sions and acts of the political department of the Government
to which this power was entrusted”).
Nevertheless, the plurality concludes that the legality of
the charge against Hamdan is doubtful because “Hamdan is
charged not with an overt act for which he was caught red
handed in a theater of war . . . but with an agreement the
inception of which long predated . . . the [relevant armed
conflict].” Ante, at 612 (emphasis in original). The plural
ity’s willingness to second-guess the Executive’s judgments
in this context, based upon little more than its unsupported
assertions, constitutes an unprecedented departure from the
traditionally limited role of the courts with respect to war
and an unwarranted intrusion on executive authority. And

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
685 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
even if such second-guessing were appropriate, the plural
ity’s attempt to do so is unpersuasive.
As an initial matter, the plurality relies upon the date of
the AUMF’s enactment to determine the beginning point for
the “period of the war,” Winthrop 836–837, thereby suggest
ing that petitioner’s commission does not have jurisdiction
to try him for offenses committed prior to the AUMF’s
enactment. Ante, at 598–600, 612. But this suggestion
betrays the plurality’s unfamiliarity with the realities of
warfare and its willful blindness to our precedents. The
starting point of the present conflict (or indeed any conflict)
is not determined by congressional enactment, but rather by
the initiation of hostilities. See Prize Cases, supra, at 668
(recognizing that war may be initiated by “invasion of a for
eign nation,” and that such initiation, and the President’s re
sponse, usually precedes congressional action). Thus, Con
gress’ enactment of the AUMF did not mark the beginning
of this Nation’s conflict with al Qaeda, but instead authorized
the President to use force in the midst of an ongoing conflict.
Moreover, while the President’s “war powers” may not have
been activated until the AUMF was passed, ante, at 599,
n. 31 (emphasis deleted), the date of such activation has
never been used to determine the scope of a military commis
sion’s jurisdiction.3 Instead, the traditional rule is that “[o]f
3 Even if the formal declaration of war were generally the determinative
act in ascertaining the temporal reach of the jurisdiction of a military
commission, the AUMF itself is inconsistent with the plurality’s sug
gestion that such a rule is appropriate in this case. See ante, at 598–600,
612. The text of the AUMF is backward looking, authorizing the use of
“all necessary and appropriate force against those nations, organizations,
or persons he determines planned, authorized, committed, or aided the
terrorist attacks that occurred on September 11, 2001.” § 2(a), 115 Stat.
224. Thus, the President’s decision to try Hamdan by military commis
sion—a use of force authorized by the AUMF—for Hamdan’s involvement
with al Qaeda prior to September 11, 2001, fits comfortably within the
framework of the AUMF. In fact, bringing the September 11 conspira

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
686 HAMDAN v. RUMSFELD
Thomas, J., dissenting
fenses committed before a formal declaration of war or be
fore the declaration of martial law may be tried by military
commission.” Green, The Military Commission, 42 Am. J.
Int’l L. 832, 848 (1948) (hereinafter Green); see also C. How
land, Digest of Opinions of the Judge-Advocates General of
the Army 1067 (1912) (hereinafter Howland) (“A military
commission . . . exercising . . . jurisdiction . . . under the laws
of war . . . may take cognizance of offenses committed, during
the war, before the initiation of the military government or
martial law” (emphasis in original)); 4 cf. Yamashita, 327
U. S., at 13 (“The extent to which the power to prosecute
violations of the law of war shall be exercised before peace
is declared rests, not with the courts, but with the political
branch of the Government”). Consistent with this principle,
on facts virtually identical to those here, a military commis
sion tried Julius Otto Kuehn for conspiring with Japanese
officials to betray the United States Fleet to the Imperial
Japanese Government prior to its attack on Pearl Harbor.
Green 848.5
tors to justice is the primary point of the AUMF. By contrast, on the
plurality’s logic, the AUMF would not grant the President the authority
to try Usama bin Laden himself for his involvement in the events of Sep
tember 11, 2001.
4 The plurality suggests these authorities are inapplicable because noth
ing in its “analysis turns on the admitted absence of either a formal decla
ration of war or a declaration of martial law. Our focus instead is on
the . . . AUMF.” Ante, at 599, n. 31. The difference identified by the
plurality is purely semantic. Both Green and Howland confirm that the
date of the enactment that establishes a legal basis for forming military
commissions—whether it be a declaration of war, a declaration of martial
law, or an authorization to use military force—does not limit the jurisdic
tion of military commissions to offenses committed after that date.
5 The plurality attempts to evade the import of this historical example
by observing that Kuehn was tried before a martial law commission for a
violation of federal espionage statutes. Ibid. As an initial matter, the
fact that Kuehn was tried before a martial law commission for an offense
committed prior to the establishment of martial law provides strong sup
port for the President’s contention that he may try Hamdan for offenses

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
687 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
Moreover, the President’s determination that the present
conflict dates at least to 1996 is supported by overwhelming
evidence. According to the State Department, al Qaeda de
clared war on the United States as early as August 1996.
See Dept. of State Fact Sheet: Usama bin Ladin (Aug. 21,
1998); Dept. of State Fact Sheet: The Charges against Inter
national Terrorist Usama Bin Laden (Dec. 20, 2000); cf. Prize
Cases, 2 Black, at 668 (recognizing that a state of war exists
even if “the declaration of it be unilateral” (emphasis in
original)). In February 1998, al Qaeda leadership issued an
other statement ordering the indiscriminate—and, even
under the laws of war as applied to legitimate nation-states,
plainly illegal—killing of American civilians and military
personnel alike. See Jihad Against Jews and Crusaders:
World Islamic Front Statement 2 (Feb. 23, 1998), in
Y. Alexander & M. Swetnam, Usama bin Laden’s al-Qaida:
Profile of a Terrorist Network, App. 1B (2001) (“The ruling
to kill the Americans and their allies—civilians and mili
tary—is an individual duty for every Muslim who can do it
in any country in which it is possible to do it”). This was
committed prior to the enactment of the AUMF. Here the AUMF serves
the same function as the declaration of martial law in Hawaii in 1941,
establishing legal authority for the constitution of military commissions.
Moreover, Kuehn was not tried and punished “by statute, but by the laws
and usages of war.” United States v. Kuehn, Board of Review 6 (Office
of the Military Governor, Hawaii 1942). Indeed, in upholding the imposi
tion of the death penalty, a sentence “not authorized by the Espionage
statutes,” id., at 5, Kuehn’s Board of Review explained that “[t]he fact
that persons may be tried and punished . . . by a military commission for
committing acts defined as offenses by . . . federal statutes does not mean
that such persons are being tried for violations of such . . . statutes; they
are, instead, being tried for acts made offenses only by orders of the . . .
commanding general,” id., at 6. Lastly, the import of this example is not
undermined by Duncan v. Kahanamoku, 327 U. S. 304 (1946). The ques
tion before the Court in that case involved only whether “loyal civilians
in loyal territory should have their daily conduct governed by military
orders,” id., at 319; it did “not involve the well-established power of the
military to exercise jurisdiction over . . . enemy belligerents,” id., at 313.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
688 HAMDAN v. RUMSFELD
Thomas, J., dissenting
not mere rhetoric; even before September 11, 2001, al Qaeda
was involved in the bombing of the World Trade Center in
New York City in 1993, the bombing of the Khobar Towers
in Saudi Arabia in 1996, the bombing of the U. S. Embassies
in Kenya and Tanzania in 1998, and the attack on the U. S. S.
Cole in Yemen in 2000. See id., at 1. In response to these
incidents, the United States “attack[ed] facilities belonging
to Usama bin Ladin’s network” as early as 1998. Dept. of
State Fact Sheet: Usama bin Ladin (Aug. 21, 1998). Based
on the foregoing, the President’s judgment—that the present
conflict substantially predates the AUMF, extending at least
as far back as al Qaeda’s 1996 declaration of war on our Na
tion, and that the theater of war extends at least as far as
the localities of al Qaeda’s principal bases of operations—is
beyond judicial reproach. And the plurality’s unsupportable
contrary determination merely confirms that “ ‘the Judiciary
has neither aptitude, facilities nor responsibility’ ” for making
military or foreign affairs judgments. Hamdi, 542 U. S., at
585 (Thomas, J., dissenting) (quoting Chicago & Southern
Air Lines, 333 U. S., at 111).
B
The third consideration identified by Winthrop’s treatise
for the exercise of military commission jurisdiction pertains
to the persons triable before such a commission, see ante, at
597–598; Winthrop 838. Law-of-war military commissions
have jurisdiction over “ ‘[i]ndividuals of the enemy’s army
who have been guilty of illegitimate warfare or other of
fences in violation of the laws of war,’ ” ante, at 598 (quoting
Winthrop 838). They also have jurisdiction over “[i]rregu
lar armed bodies or persons not forming part of the orga
nized forces of a belligerent” “who would not be likely to
respect the laws of war.” Id., at 783, 784. Indeed, accord
ing to Winthrop, such persons are not “within the protection
of the laws of war” and were “liable to be shot, imprisoned,
or banished, either summarily where their guilt was clear or

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
689 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
upon trial and conviction by military commission.” Id., at
784. This consideration is easily satisfied here, as Hamdan
is an unlawful combatant charged with joining and conspir
ing with a terrorist network dedicated to flouting the laws
of war. 344 F. Supp. 2d 152, 161 (DC 2004); App. to Pet. for
Cert. 63a–67a.
C
The fourth consideration relevant to the jurisdiction of
law-of-war military commissions relates to the nature of the
offense charged. As relevant here, such commissions have
jurisdiction to try “ ‘[v]iolations of the laws and usages of war
cognizable by military tribunals only,’ ” ante, at 598 (quoting
Winthrop 839). In contrast to the preceding considerations,
this Court’s precedents establish that judicial review of
“whether any of the acts charged is an offense against the
law of war cognizable before a military tribunal” is appro
priate. Quirin, 317 U. S., at 29. However, “charges of vio
lations of the law of war triable before a military tribunal
need not be stated with the precision of a common law indict
ment.” Yamashita, 327 U. S., at 17. And whether an of
fense is a violation of the law of war cognizable before a
military commission must be determined pursuant to “the
system of common law applied by military tribunals.”
Quirin, supra, at 30; Yamashita, supra, at 8.
The common law of war as it pertains to offenses triable
by military commission is derived from the “experience of
our wars” and our wartime tribunals, Winthrop 839, and “the
laws and usages of war as understood and practiced by the
civilized nations of the world,” 11 Op. Atty. Gen. 297, 310
(1865). Moreover, the common law of war is marked by two
important features. First, as with the common law gener
ally, it is flexible and evolutionary in nature, building upon
the experience of the past and taking account of the exigen
cies of the present. Thus, “[t]he law of war, like every other
code of laws, declares what shall not be done, and does not
say what may be done. The legitimate use of the great

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
690 HAMDAN v. RUMSFELD
Thomas, J., dissenting
power of war, or rather the prohibitions upon the use of that
power, increase or diminish as the necessity of the case de
mands.” Id., at 300. Accordingly, this Court has recog
nized that the “jurisdiction” of “our common-law war courts”
has not been “prescribed by statute,” but rather “has been
adapted in each instance to the need that called it forth.”
Madsen, 343 U. S., at 346–348. Second, the common law of
war affords a measure of respect for the judgment of military
commanders. Thus, “[t]he commander of an army in time of
war has the same power to organize military tribunals and
execute their judgments that he has to set his squadrons in
the field and fight battles. His authority in each case is from
the law and usage of war.” 11 Op. Atty. Gen., at 305. In
recognition of these principles, Congress has generally “ ‘left
it to the President, and the military commanders represent
ing him, to employ the commission, as occasion may require,
for the investigation and punishment of violations of the laws
of war.’ ” Madsen, supra, at 347, n. 9 (quoting Winthrop
831; emphasis added).
In one key respect, the plurality departs from the proper
framework for evaluating the adequacy of the charge against
Hamdan under the laws of war. The plurality holds that
where, as here, “neither the elements of the offense nor the
range of permissible punishments is defined by statute or
treaty, the precedent [establishing whether an offense is tri
able by military commission] must be plain and unambigu
ous.” Ante, at 602. This is a pure contrivance, and a bad
one at that. It is contrary to the presumption we acknowl
edged in Quirin, namely, that the actions of military commis
sions are “not to be set aside by the courts without the clear
conviction that they are” unlawful, 317 U. S., at 25 (emphasis
added). It is also contrary to Yamashita, which recognized
the legitimacy of that military commission notwithstanding
a substantial disagreement pertaining to whether Yamashita
had been charged with a violation of the law of war. Com
pare 327 U. S., at 17 (noting that the allegations were “ade

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
691 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
quat[e]” and “need not be stated with . . . precision”), with
id., at 35 (Murphy, J., dissenting) (arguing that the charge
was inadequate). Nor does it find support from the
separation-of-powers authority cited by the plurality. In
deed, Madison’s praise of the separation of powers in The
Federalist No. 47, quoted ante, at 602, if it has any relevance
at all, merely highlights the illegitimacy of today’s judicial
intrusion onto core executive prerogatives in the waging of
war, where executive competence is at its zenith and judicial
competence at its nadir.
The plurality’s newly minted clear-statement rule is also
fundamentally inconsistent with the nature of the common
law which, by definition, evolves and develops over time and
does not, in all cases, “say what may be done.” 11 Op. Atty.
Gen., at 300. Similarly, it is inconsistent with the nature
of warfare, which also evolves and changes over time, and
for which a flexible, evolutionary common-law system is
uniquely appropriate.6 Though the charge against Hamdan
easily satisfies even the plurality’s manufactured rule, see
infra, at 692–706, the plurality’s inflexible approach has dan
gerous implications for the Executive’s ability to discharge
his duties as Commander in Chief in future cases. We
should undertake to determine whether an unlawful combat
ant has been charged with an offense against the law of war
with an understanding that the common law of war is flexi
ble, responsive to the exigencies of the present conflict, and
deferential to the judgment of military commanders.
6 Indeed, respecting the present conflict, the President has found that
“the war against terrorism ushers in a new paradigm, one in which groups
with broad, international reach commit horrific acts against innocent civil
ians, sometimes with the direct support of states. Our Nation recognizes
that this new paradigm—ushered in not by us, but by terrorists—requires
new thinking in the law of war.” App. 34–35. Under the Court’s ap
proach, the President’s ability to address this “new paradigm” of inflicting
death and mayhem would be completely frozen by rules developed in the
context of conventional warfare.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
692 HAMDAN v. RUMSFELD
Thomas, J., dissenting
1
Under either the correct, flexible approach to evaluating
the adequacy of Hamdan’s charge, or under the plurality’s
new, clear-statement approach, Hamdan has been charged
with conduct constituting two distinct violations of the law
of war cognizable before a military commission: membership
in a war-criminal enterprise and conspiracy to commit war
crimes. The charging section of the indictment alleges both
that Hamdan “willfully and knowingly joined an enterprise
of persons who shared a common criminal purpose,” App. to
Pet. for Cert. 65a, and that he “conspired and agreed with
[al Qaeda] to commit . . . offenses triable by military commis
sion,” ibid.7
7 It is true that both of these separate offenses are charged under a
single heading entitled “CHARGE: CONSPIRACY,” App. to Pet. for Cert.
65a. But that does not mean that they must be treated as a single crime,
when the law of war treats them as separate crimes. As we acknowl
edged in In re Yamashita, 327 U. S. 1 (1946), “charges of violations of the
law of war triable before a military tribunal need not be stated with the
precision of a common law indictment.” Id., at 17; cf. W. Birkhimer, Mili
tary Government and Martial Law 536 (3d rev. ed. 1914) (hereinafter
Birkhimer) (“[I]t would be extremely absurd to expect the same precision
in a charge brought before a court-martial as is required to support
a conviction before a justice of the peace” (internal quotation marks
omitted)).
Nevertheless, the plurality contends that Hamdan was “not actually
charged,” ante, at 601, n. 32 (emphasis deleted), with being a member in
a war-criminal organization. But that position is demonstrably wrong.
Hamdan’s charging document expressly charges that he “willfully and
knowingly joined an enterprise of persons who shared a common criminal
purpose.” App. to Pet. for Cert. 65a. Moreover, the plurality’s conten
tion that we may only look to the label affixed to the charge to determine
if the charging document alleges an offense triable by military commission
is flatly inconsistent with its treatment of the Civil War cases—where it
accepts as valid charges that did not appear in the heading or title of the
charging document, or even the listed charge itself, but only in the sup
porting specification. See, e. g., ante, at 609 (discussing the military com
mission trial of Wirz). For example, in the Wirz case, Wirz was charged

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
693 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
The common law of war establishes that Hamdan’s willful
and knowing membership in al Qaeda is a war crime charge
able before a military commission. Hamdan, a confirmed
enemy combatant and member or affiliate of al Qaeda, has
been charged with willfully and knowingly joining a group
(al Qaeda) whose purpose is “to support violent attacks
against property and nationals (both military and civilian)
of the United States.” Id., at 64a; 344 F. Supp. 2d, at 161.
Moreover, the allegations specify that Hamdan joined and
maintained his relationship with al Qaeda even though he
“believed that Usama bin Laden and his associates were in
volved in the attacks on the U. S. Embassies in Kenya and
Tanzania in August 1998, the attack on the USS COLE in
October 2000, and the attacks on the United States on Sep
tember 11, 2001.” App. to Pet. for Cert. 65a. These alle
gations, against a confirmed unlawful combatant, are alone
sufficient to sustain the jurisdiction of Hamdan’s military
commission.
For well over a century it has been established that “to
unite with banditti, jayhawkers, guerillas, or any other unau
thorized marauders is a high offence against the laws of war;
the offence is complete when the band is organized or joined.
The atrocities committed by such a band do not constitute
the offence, but make the reasons, and sufficient reasons
they are, why such banditti are denounced by the laws of
with conspiring to violate the laws of war, and that charge was supported
with allegations that he personally committed a number of atrocities.
The plurality concludes that military commission jurisdiction was appro
priate in that case not based upon the charge of conspiracy, but rather
based upon the allegations of various atrocities in the specification which
were not separately charged. Ante, at 609. Just as these atrocities, not
separately charged, were independent violations of the law of war support
ing Wirz’s trial by military commission, so too here Hamdan’s membership
in al Qaeda and his provision of various forms of assistance to al Qaeda’s
top leadership are independent violations of the law of war supporting his
trial by military commission.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
694 HAMDAN v. RUMSFELD
Thomas, J., dissenting
war.” 11 Op. Atty. Gen., at 312 (emphasis added).8 In other
words, unlawful combatants, such as Hamdan, violate the law
of war merely by joining an organization, such as al Qaeda,
whose principal purpose is the “killing [and] disabling . . . of
peaceable citizens or soldiers.” Winthrop 784; see also 11
Op. Atty. Gen., at 314 (“A bushwhacker, a jayhawker, a ban
dit, a war rebel, an assassin, being public enemies, may be
tried, condemned, and executed as offenders against the laws
of war”). This conclusion is unsurprising, as it is a “cardinal
principle of the law of war . . . that the civilian population
must enjoy complete immunity.” 4 Int’l Comm. of Red
Cross, Commentary: Geneva Convention Relative to the Pro
tection of Civilian Persons in Time of War 3 (J. Pictet gen.
ed. 1958). “Numerous instances of trials, for ‘Violation of
the laws of war,’ of offenders of this description, are pub
lished in the General Orders of the years 1862 to 1866.”
Winthrop 784, and n. 57.9 Accordingly, on this basis alone,
8 These observations respecting the law of war were made by the Attor
ney General in defense of the military commission trial of the Lincoln
conspirators. As the foregoing quoted portion of that opinion makes
clear, the Attorney General did not, as the plurality maintains, “trea[t] the
charge as if it alleged the substantive offense of assassination.” Ante, at
604, n. 35. Rather, he explained that the conspirators’ “high offence
against the laws of war” was “complete” when their band was “organized
or joined,” and did not depend upon “atrocities committed by such a band.”
11 Op. Atty. Gen. 297, 312 (1865). Moreover, the Attorney General’s con
clusions specifically refute the plurality’s unsupported suggestion that I
have blurred the line between “those categories of ‘offender’ who may be
tried by military commission . . . with the ‘offenses’ that may be so tried.”
Ante, at 601, n. 32.
9 The General Orders establishing the jurisdiction for military commis
sions during the Civil War provided that such offenses were violations
of the laws of war cognizable before military commissions. See H. R.
Doc. No. 65, 55th Cong., 3d Sess., 164 (1894) (“[P]ersons charged with the
violation of the laws of war as spies, bridge-burners, marauders, &c.,
will . . . be held for trial under such charges”); id., at 234 (“[T]here are
numerous rebels . . . that . . . furnish the enemy with arms, provisions,
clothing, horses and means of transportation; [such] insurgents are band
ing together in several of the interior counties for the purpose of assisting

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
695 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
“the allegations of [Hamdan’s] charge, tested by any reason
able standard, adequately allege a violation of the law of
war.” Yamashita, 327 U. S., at 17.
The conclusion that membership in an organization whose
purpose is to violate the laws of war is an offense triable by
military commission is confirmed by the experience of the
the enemy to rob, to maraud and to lay waste the country. All such per
sons are by the laws of war in every civilized country liable to capital
punishment” (emphasis added)). Numerous trials were held under this
authority. See, e. g., U. S. War Dept., General Court Martial Order No. 51,
p. 1 (1866) (hereinafter G. C. M. O.) (indictment in the military commission
trial of James Harvey Wells charged “ ‘[b]eing a guerrilla’ ” and specified
that he “ ‘willfully . . . [took] up arms as a guerrilla marauder, and did
join, belong to, act and co-operate with guerrillas’ ”); G. C. M. O. No. 108,
Head-Quarters Dept. of Kentucky, p. 1 (1865) (indictment in the military
commission trial of Henry C. Magruder charged “ ‘[b]eing a guerrilla’ ” and
specified that he “ ‘unlawfully, and of his own wrong, [took] up arms as a
guerrilla marauder, and did join, belong to, act, and co-operate with a band
of guerrillas’ ”); G. C. M. O. No. 41, p. 1 (1864) (indictment in the military
commission trial of John West Wilson charged that Wilson “ ‘did take up
arms as an insurgent and guerrilla against the laws and authorities of the
United States, and did join and co-operate with an armed band of insur
gents and guerrillas who were engaged in plundering the property of
peaceable citizens . . . in violation of the laws and customs of war’ ”);
G. C. M. O. No. 153, p. 1 (1864) (indictment in the military commission trial
of Simeon B. Kight charged that defendant was “ ‘a guerrilla, and has been
engaged in an unwarrantable and barbarous system of warfare against
citizens and soldiers of the United States’ ”); G. C. M. O. No. 93, pp. 3–4
(1864) (indictment in the military commission trial of Francis H. Norvel
charged “ ‘[b]eing a guerrilla’ ” and specified that he “ ‘unlawfully and by
his own wrong, [took] up arms as an outlaw, guerrilla, and bushwhacker,
against the lawfully constituted authorities of the United States govern
ment’ ”); id., at 9 (indictment in the military commission trial of James A.
Powell charged “ ‘[t]ransgression of the laws and customs of war’ ” and
specified that he “ ‘[took] up arms in insurrection as a military insurgent,
and did join himself to and, in arms, consort with . . . a rebel enemy of the
United States, and the leader of a band of insurgents and armed rebels’ ”);
id., at 10–11 (indictment in the military commission trial of Joseph
Overstreet charged “ ‘[b]eing a guerrilla’ ” and specified that he “ ‘did join,
belong to, consort and co-operate with a band of guerrillas, insurgents,
outlaws, and public robbers’ ”).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
696 HAMDAN v. RUMSFELD
Thomas, J., dissenting
military tribunals convened by the United States at Nur
emberg. Pursuant to Article 10 of the Charter of the Inter
national Military Tribunal (IMT), the United States con
vened military tribunals “to bring individuals to trial for
membership” in “a group or organization . . . declared crimi
nal by the [IMT].” 1 Trials of War Criminals Before the
Nuernberg Military Tribunals, p. XII, Art. 10 (hereinafter
Trials). The IMT designated various components of four
Nazi groups—the Leadership Corps, Gestapo, SD, and SS—
as criminal organizations. 22 IMT, Trial of the Major War
Criminals 505, 511, 517 (1948); see also T. Taylor, Anatomy
of the Nuremberg Trials: A Personal Memoir 584–585 (1992).
“[A] member of [such] an organization [could] be . . . convicted
of the crime of membership and be punished for that crime
by death.” 22 IMT, at 499. Under this authority, the
United States Military Tribunal at Nuremberg convicted nu
merous individuals for the act of knowing and voluntary
membership in these organizations. For example, in Mili
tary Tribunal Case No. 1, United States v. Brandt, Karl
Brandt, Karl Gebhardt, Rudolf Brandt, Joachim Mrugowsky,
Wolfram Sievers, Viktor Brack, and Waldemar Hoven were
convicted and sentenced to death for the crime of, inter alia,
membership in an organization declared criminal by the
IMT; Karl Genzken and Fritz Fischer were sentenced to life
imprisonment for the same; and Helmut Poppendick was con
victed of no other offense than membership in a criminal
organization and sentenced to a 10-year term of imprison
ment. 2 Trials 180–300. This Court denied habeas relief,
333 U. S. 836 (1948), and the executions were carried out at
Landsberg prison on June 2, 1948. 2 Trials 330.
Moreover, the Government has alleged that Hamdan was
not only a member of al Qaeda while it was carrying out
terrorist attacks on civilian targets in the United States and
abroad, but also that Hamdan aided and assisted al Qaeda’s
top leadership by supplying weapons, transportation, and
other services. App. to Pet. for Cert. 65a–67a. These alle

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
697 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
gations further confirm that Hamdan is triable before a law
of-war military commission for his involvement with al
Qaeda. See H. R. Doc. No. 65, 55th Cong., 3d Sess., 234
(1894) (“[T]here are numerous rebels . . . that . . . furnish the
enemy with arms, provisions, clothing, horses and means of
transportation; [such] insurgents are banding together in
several of the interior counties for the purpose of assisting
the enemy to rob, to maraud and to lay waste [to] the country.
All such persons are by the laws of war in every civilized
country liable to capital punishment” (emphasis added));
Winthrop 840 (including in the list of offenses triable by law
of-war military commissions “dealing with . . . enemies, or
furnishing them with money, arms, provisions, medicines,
& c.”).10 Undoubtedly, the conclusion that such conduct vio
lates the law of war led to the enactment of Article 104 of
the UCMJ, which provides that “[a]ny person who . . . aids, or
attempts to aid, the enemy with arms, ammunition, supplies,
money, or other things . . . shall suffer death or such other
punishment as a court-martial or military commission may
direct.” 10 U. S. C. § 904.
2
Separate and apart from the offense of joining a contingent
of “uncivilized combatants who [are] not . . . likely to respect
the laws of war,” Winthrop 784, Hamdan has been charged
with “conspir[ing] and agree[ing] with . . . the al Qaida
organization . . . to commit . . . offenses triable by military
commission,” App. to Pet. for Cert. 65a. Those offenses in
clude “attacking civilians; attacking civilian objects; murder
by an unprivileged belligerent; and terrorism.” Ibid. This,
10 Even if the plurality were correct that a membership offense must be
accompanied by allegations that the “defendant ‘took up arms,’ ” ante, at
601, n. 32, that requirement has easily been satisfied here. Not only has
Hamdan been charged with providing assistance to top al Qaeda leader
ship (itself an offense triable by military commission), he has also been
charged with receiving weapons training at an al Qaeda camp. App. to
Pet. for Cert. 66a–67a.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
698 HAMDAN v. RUMSFELD
Thomas, J., dissenting
too, alleges a violation of the law of war triable by military
commission.
“[T]he experience of our wars,” Winthrop 839, is rife with
evidence that establishes beyond any doubt that conspiracy
to violate the laws of war is itself an offense cognizable be
fore a law-of-war military commission. World War II pro
vides the most recent examples of the use of American mili
tary commissions to try offenses pertaining to violations of
the laws of war. In that conflict, the orders establishing the
jurisdiction of military commissions in various theaters of
operation provided that conspiracy to violate the laws of war
was a cognizable offense. See Letter, General Headquar
ters, United States Army Forces, Pacific (Sept. 24, 1945),
Record in Yamashita v. Styer, O. T. 1945, No. 672, pp. 14, 16
(Exh. F) (Order respecting the “Regulations Governing the
Trial of War Criminals” provided that “participation in a
common plan or conspiracy to accomplish” various offenses
against the law of war was cognizable before military com
missions); 1 U. N. War Crimes Commission, Law Reports of
Trials of War Criminals 114–115 (1947) (reprint 1997) (here
inafter U. N. Commission) (recounting that the orders estab
lishing World War II military commissions in the Pacific and
China included “participation in a common plan or conspir
acy” pertaining to certain violations of the laws of war as
an offense triable by military commission). Indeed, those
orders authorized trial by military commission of participa
tion in a conspiracy to commit “ ‘murder . . . or other inhu
mane acts . . . against any civilian population,’ ” id., at 114,
which is precisely the offense Hamdan has been charged with
here. And conspiracy to violate the laws of war was
charged in the highest profile case tried before a World War
II military commission, see Quirin, 317 U. S., at 23, and on
numerous other occasions. See, e. g., Colepaugh v. Looney,
235 F. 2d 429, 431 (CA10 1956); Green 848 (describing the
conspiracy trial of Julius Otto Kuehn).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
699 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
To support its contrary conclusion, ante, at 600, the plural
ity attempts to evade the import of Quirin (and the other
World War II authorities) by resting upon this Court’s fail
ure to address the sufficiency of the conspiracy charge in the
Quirin case, ante, at 605–607. But the common law of war
cannot be ascertained from this Court’s failure to pass upon
an issue, or indeed to even mention the issue in its opinion;11
rather, it is ascertained by the practice and usage of war.
Winthrop 839; supra, at 689–690.
The Civil War experience provides further support for the
President’s conclusion that conspiracy to violate the laws of
war is an offense cognizable before law-of-war military com
missions. Indeed, in the highest profile case to be tried be
fore a military commission relating to that war, namely, the
trial of the men involved in the assassination of President
Lincoln, the charge provided that those men had “com
bin[ed], confederat[ed], and conspir[ed] . . . to kill and mur
der” President Lincoln. G. C. M. O. No. 356 (1865), re
printed in H. R. Doc. No. 314, 55th Cong., 3d Sess., 696 (1899)
(hereinafter G. C. M. O. No. 356).12
11 The plurality recounts the respective claims of the parties in Quirin
pertaining to this issue and cites the United States Reports. Ante, at
605. But the claims of the parties are not included in the opinion of the
Court, but rather in the sections of the Reports entitled “Argument for
Petitioners” and “Argument for Respondent.” See 317 U. S., at 6–17.
12 The plurality concludes that military commission jurisdiction was ap
propriate in the case of the Lincoln conspirators because they were
charged with “ ‘maliciously, unlawfully, and traitorously murdering the
said Abraham Lincoln,’ ” ante, at 604, n. 35. But the sole charge filed in
that case alleged conspiracy, and the allegations pertaining to “maliciously,
unlawfully, and traitorously murdering the said Abraham Lincoln” were
not charged or labeled as separate offenses, but rather as overt acts “in
pursuance of and in prosecuting said malicious, unlawful, and traitorous
conspiracy.” G. C. M. O. No. 356, at 696 (emphasis added). While the
plurality contends the murder of President Lincoln was charged as a
distinct separate offense, the foregoing quoted language of the charging
document unequivocally establishes otherwise. Moreover, though I agree
that the allegations pertaining to these overt acts provided an independ

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
700 HAMDAN v. RUMSFELD
Thomas, J., dissenting
In addition to the foregoing high-profile example, Win
throp’s treatise enumerates numerous Civil War military
commission trials for conspiracy to violate the law of war.
Winthrop 839, n. 5. The plurality attempts to explain these
examples away by suggesting that the conspiracies listed by
Winthrop are best understood as “a species of compound of
fense,” namely, violations both of the law of war and ordinary
criminal laws, rather than “stand-alone offense[s] against the
law of war.” Ante, at 608 (citing, as an example, murder
in violation of the laws of war). But the fact that, for exam
ple, conspiracy to commit murder can at the same time vio
late ordinary criminal laws and the law of war, so that it is
“a combination of the two species of offenses,” Howland 1071,
does not establish that a military commission would not have
jurisdiction to try that crime solely on the basis that it was
a violation of the law of war. Rather, if anything, and con
sistent with the principle that the common law of war is flex
ible and affords some level of deference to the judgments of
military commanders, it establishes that military commis
sions would have the discretion to try the offense as (1) one
against the law of war, or (2) one against the ordinary crimi
nal laws, or (3) both.
In any event, the plurality’s effort to avoid the import of
Winthrop’s footnote through the smokescreen of its “com
pound offense” theory, ante, at 607–608, cannot be reconciled
with the particular charges that sustained military commis
sion jurisdiction in the cases that Winthrop cites. For ex
ent basis for the military commission’s jurisdiction in that case, that
merely confirms the propriety of examining all the acts alleged—whether
or not they are labeled as separate offenses—to determine if a defendant
has been charged with a violation of the law of war. As I have already
explained, Hamdan has been charged with violating the law of war not
only by participating in a conspiracy to violate the law of war, but also by
joining a war-criminal enterprise and by supplying provisions and assist
ance to that enterprise’s top leadership.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
701 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
ample, in the military commission trial of Henry Wirz,
Charge I provided that he had been
“[m]aliciously, willfully, and traitorously . . . combining,
confederating, and conspiring, together [with various
other named and unnamed co-conspirators], to injure the
health and destroy the lives of soldiers in the military
service of the United States, then held and being prison
ers of war within the lines of the so-called Confederate
States, and in the military prisons thereof, to the end
that the armies of the United States might be weakened
and impaired, in violation of the laws and customs of
war.” G. C. M. O. No. 607 (1865), reprinted in H. R.
Doc. No. 314, at 785 (emphasis added).
Likewise, in the military commission trial of Leger Grenfel,
Charge I accused Grenfel of “[c]onspiring, in violation of
the laws of war, to release rebel prisoners of war confined
by authority of the United States at Camp Douglas, near
Chicago, Ill.” G. C. M. O. No. 452 (1865), reprinted in H. R.
Doc. No. 314, at 724 (emphasis added); 13 see also G. C. M. O.
13 The plurality’s attempt to undermine the significance of these cases is
unpersuasive. The plurality suggests the Wirz case is not relevant be
cause the specification supporting his conspiracy charge alleged that he
“personally committed a number of atrocities.” Ante, at 609. But this
does not establish that conspiracy to violate the laws of war, the very
crime with which Wirz was charged, is not itself a violation of the law of
war. Rather, at best, it establishes that in addition to conspiracy Wirz
violated the laws of war by committing various atrocities, just as Hamdan
violated the laws of war not only by conspiring to do so, but also by joining
al Qaeda and providing provisions and services to its top leadership.
Moreover, the fact that Wirz was charged with overt acts that are more
severe than the overt acts with which Hamdan has been charged does
not establish that conspiracy is not an offense cognizable before military
commission; rather it merely establishes that Wirz’s offenses may have
been comparably worse than Hamdan’s offenses.
The plurality’s claim that the charge against Leger Grenfel supports its
compound offense theory is similarly unsupportable. The plurality does
not, and cannot, dispute that Grenfel was charged with conspiring to vio

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
702 HAMDAN v. RUMSFELD
Thomas, J., dissenting
No. 41, p. 20 (1864) (indictment in the military commission
trial of Robert Louden charged “ ‘[c]onspiring with the rebel
enemies of the United States to embarrass and impede the
military authorities in the suppression of the existing rebel
lion, by the burning and destruction of steamboats and
means of transportation on the Mississippi river’ ”). These
examples provide incontrovertible support for the Presi
dent’s conclusion that the common law of war permits mili
tary commission trials for conspiracy to violate the law of
war. And they specifically contradict the plurality’s conclu
sion to the contrary, thereby easily satisfying its require
ment that the Government “make a substantial showing that
the crime for which it seeks to try a defendant by military
commission is acknowledged to be an offense against the law
of war.” Ante, at 603.14
late the laws of war by releasing rebel prisoners—a charge that bears no
relation to a crime “ordinarily triable in civilian courts.” Ante, at 609,
n. 37. Tellingly, the plurality does not reference or discuss this charge,
but instead refers to the conclusion of Judge Advocate Holt that Grenfel
also “ ‘united himself with traitors and malefactors for the overthrow of
our Republic in the interest of slavery.’ ” Ante, at 610, n. 37 (quoting
H. R. Doc. No. 314, at 689). But Judge Advocate Holt’s observation pro
vides no support for the plurality’s conclusion, as it does not discuss the
charges that sustained military commission jurisdiction, much less suggest
that such charges were not violations of the law of war.
14 The plurality contends that international practice—including the prac
tice of the IMT at Nuremberg—supports its conclusion that conspiracy is
not an offense triable by military commission because “ ‘[t]he Anglo-
American concept of conspiracy was not part of European legal systems
and arguably not an element of the internationally recognized laws of
war.’ ” Ante, at 611 (quoting T. Taylor, Anatomy of the Nuremberg
Trials: A Personal Memoir 36 (1992)). But while the IMT did not crimi
nalize all conspiracies to violate the law of war, it did criminalize “partici
pation in a common plan or conspiracy” to wage aggressive war. See 1
Trials, at XI–XII, Art. 6(a). Moreover, the World War II military tribu
nals of several European nations recognized conspiracy to violate the laws
of war as an offense triable before military commissions. See 15 U. N.
Commission 90–91 (noting that the French Military Tribunal at Marseilles
found Henri Georges Stadelhofer “guilty of the crime of association
de malfaiteurs,” namely, of “ ‘having formed with various members of the

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
703 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
The plurality further contends, in reliance upon Winthrop,
that conspiracy is not an offense cognizable before a law-of
war military commission because “it is not enough to intend
to violate the law of war and commit overt acts in further
ance of that intention unless the overt acts either are them
selves offenses against the law of war or constitute steps
sufficiently substantial to qualify as an attempt.” Ante, at
604. But Winthrop does not support the plurality’s conclu
sion. The passage in Winthrop cited by the plurality states
only that “the jurisdiction of the military commission should
be restricted to cases of offence consisting in overt acts, i. e.
in unlawful commissions or actual attempts to commit, and
not in intentions merely.” Winthrop 841 (emphasis in origi
nal). This passage would be helpful to the plurality if its
subject were “conspiracy,” rather than the “jurisdiction of
the military commission.” Winthrop is not speaking here of
the requirements for a conspiracy charge, but of the require
ments for all charges. Intentions do not suffice. An unlaw
ful act—such as committing the crime of conspiracy—is nec
essary. Winthrop says nothing to exclude either conspiracy
or membership in a criminal enterprise, both of which go
beyond “intentions merely” and “consis[t of] overt acts,
i. e. . . . unlawful commissions or actual attempts to commit,”
and both of which are expressly recognized by Winthrop as
crimes against the law of war triable by military commis
sions. Id., at 784; id., at 839, and n. 5, 840. Indeed, the
German Gestapo an association with the aim of preparing or committing
crimes against persons or property, without justification under the laws
and usages of war’ ”); 11 id., at 98 (noting that the Netherlands’ military
tribunals were authorized to try conspiracy to violate the laws of war).
Thus, the European legal systems’ approach to domestic conspiracy law
has not prevented European nations from recognizing conspiracy offenses
as violations of the law of war. This is unsurprising, as the law of war is
derived not from domestic law but from the wartime practices of civilized
nations, including the United States, which has consistently recognized
that conspiracy to violate the laws of war is an offense triable by mili
tary commission.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
704 HAMDAN v. RUMSFELD
Thomas, J., dissenting
commission of an “overt ac[t]” is the traditional requirement
for the completion of the crime of conspiracy, and the charge
against Hamdan alleges numerous such overt acts. App. to
Pet. for Cert. 65a. The plurality’s approach, unsupported by
Winthrop, requires that any overt act to further a conspiracy
must itself be a completed war crime distinct from conspir
acy—which merely begs the question the plurality sets out
to answer, namely, whether conspiracy itself may constitute
a violation of the law of war. And, even the plurality’s un
supported standard is satisfied here. Hamdan has been
charged with the overt acts of providing protection, trans
portation, weapons, and other services to the enemy, id., at
65a–67a, acts which in and of themselves are violations of
the laws of war. See supra, at 696–697; Winthrop 839–840.
3
Ultimately, the plurality’s determination that Hamdan has
not been charged with an offense triable before a military
commission rests not upon any historical example or author
ity, but upon the plurality’s raw judgment of the “inability
on the Executive’s part here to satisfy the most basic
precondition . . . for establishment of military commissions:
military necessity.” Ante, at 612. This judgment starkly
confirms that the plurality has appointed itself the ultimate
arbiter of what is quintessentially a policy and military judg
ment, namely, the appropriate military measures to take
against those who “aided the terrorist attacks that occurred
on September 11, 2001.” AUMF § 2(a), 115 Stat. 224. The
plurality’s suggestion that Hamdan’s commission is illegiti
mate because it is not dispensing swift justice on the battle
field is unsupportable. Ante, at 607. Even a cursory re
view of the authorities confirms that law-of-war military
commissions have wide-ranging jurisdiction to try offenses
against the law of war in exigent and nonexigent circum
stances alike. See, e. g., Winthrop 839–840; see also Yamas
hita, 327 U. S., at 5 (military commission trial after the cessa

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
705 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
tion of hostilities in the Philippines); Quirin, 317 U. S. 1
(military commission trial in Washington, D. C.). Tradition
ally, retributive justice for heinous war crimes is as much a
“military necessity” as the “demands” of “military efficiency”
touted by the plurality, and swift military retribution is pre
cisely what Congress authorized the President to impose on
the September 11 attackers in the AUMF.
Today a plurality of this Court would hold that conspiracy
to massacre innocent civilians does not violate the laws of
war. This determination is unsustainable. The judgment
of the political branches that Hamdan, and others like him,
must be held accountable before military commissions for
their involvement with and membership in an unlawful orga
nization dedicated to inflicting massive civilian casualties is
supported by virtually every relevant authority, including all
of the authorities invoked by the plurality today. It is also
supported by the nature of the present conflict. We are not
engaged in a traditional battle with a nation-state, but with
a worldwide, hydra-headed enemy, who lurks in the shadows
conspiring to reproduce the atrocities of September 11, 2001,
and who has boasted of sending suicide bombers into civilian
gatherings, has proudly distributed videotapes of beheadings
of civilian workers, and has tortured and dismembered cap
tured American soldiers. But according to the plurality,
when our Armed Forces capture those who are plotting ter
rorist atrocities like the bombing of the Khobar Towers, the
bombing of the U. S. S. Cole, and the attacks of September
11—even if their plots are advanced to the very brink of
fulfillment—our military cannot charge those criminals with
any offense against the laws of war. Instead, our troops
must catch the terrorists “redhanded,” ante, at 612, in the
midst of the attack itself, in order to bring them to justice.
Not only is this conclusion fundamentally inconsistent with
the cardinal principle of the law of war, namely, protecting
noncombatants, but it would sorely hamper the President’s
ability to confront and defeat a new and deadly enemy.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
706 HAMDAN v. RUMSFELD
Thomas, J., dissenting
After seeing the plurality overturn longstanding prece
dents in order to seize jurisdiction over this case, ante, at
656–658 (Scalia, J., dissenting), and after seeing them disre
gard the clear prudential counsel that they abstain in these
circumstances from using equitable powers, ante, at 672–678,
it is no surprise to see them go on to overrule one after
another of the President’s judgments pertaining to the con
duct of an ongoing war. Those Justices who today disregard
the Commander in Chief ’s wartime decisions, only 10 days
ago deferred to the judgment of the Corps of Engineers with
regard to a matter much more within the competence of law
yers, upholding that agency’s wildly implausible conclusion
that a storm drain is a tributary of the waters of the United
States. See Rapanos v. United States, 547 U. S. 715 (2006).
It goes without saying that there is much more at stake here
than storm drains. The plurality’s willingness to second
guess the determination of the political branches that these
conspirators must be brought to justice is both unprece
dented and dangerous.
III
The Court holds that even if “the Government has charged
Hamdan with an offense against the law of war cognizable by
military commission, the commission lacks power to proceed”
because of its failure to comply with the terms of the UCMJ
and the four Geneva Conventions signed in 1949. Ante,
at 613. This position is untenable.
A
As with the jurisdiction of military commissions, the pro
cedure of such commissions “has [not] been prescribed by
statute,” but “has been adapted in each instance to the need
that called it forth.” Madsen, 343 U. S., at 347–348. In
deed, this Court has concluded that “[i]n the absence of at
tempts by Congress to limit the President’s power, it appears
that, as Commander-in-Chief of the Army and Navy of the
United States, he may, in time of war, establish and prescribe

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
707 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
the jurisdiction and procedure of military commissions.”
Id., at 348. This conclusion is consistent with this Court’s
understanding that military commissions are “our common
law war courts.” Id., at 346–347.15 As such, “[s]hould the
conduct of those who compose martial-law tribunals become
[a] matter of judicial determination subsequently before the
civil courts, those courts will give great weight to the opin
ions of the officers as to what the customs of war in any case
justify and render necessary.” Birkhimer 534.
15 Though it does not constitute a basis for any holding of the Court, the
Court maintains that, as a “general rule,” “the procedures governing trials
by military commission historically have been the same as those governing
courts-martial.” Ante, at 617. While it is undoubtedly true that mili
tary commissions have invariably employed most of the procedures em
ployed by courts-martial, that is not a requirement. See Winthrop 841
(“[M]ilitary commissions . . . are commonly conducted according to the
rules and forms governing courts-martial. These war-courts are indeed
more summary in their action than are the courts held under the Articles
of war, and . . . their proceedings . . . will not be rendered illegal by the
omission of details required upon trials by courts-martial” (emphasis in
original; footnotes omitted)); 1 U. N. Commission 116–117 (“The [World
War II] Mediterranean Regulations (No. 8) provide that Military Commis
sions shall conduct their proceedings as may be deemed necessary for full
and fair trial, having regard for, but not being bound by, the rules of
procedure prescribed for General Courts Martial” (emphasis added)); id.,
at 117 (“In the [World War II] European directive it is stated . . . that
Military Commissions shall have power to make, as occasion requires, such
rules for the conduct of their proceedings consistent with the powers of
such Commissions, and with the rules of procedure . . . as are deemed
necessary for a full and fair trial of the accused, having regard for, without
being bound by, the rules of procedure and evidence prescribed for Gen
eral Courts Martial”). Moreover, such a requirement would conflict with
the settled understanding of the flexible and responsive nature of military
commissions and the President’s wartime authority to employ such tribu
nals as he sees fit. See Birkhimer 537–538 (“[M]ilitary commissions may
so vary their procedure as to adapt it to any situation, and may extend
their powers to any necessary degree. . . . The military commander decides
upon the character of the military tribunal which is suited to the
occasion . . . and his decision is final”).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
708 HAMDAN v. RUMSFELD
Thomas, J., dissenting
The Court nevertheless concludes that at least one provi
sion of the UCMJ amounts to an attempt by Congress to
limit the President’s power. This conclusion is not only con
trary to the text and structure of the UCMJ, but it is also
inconsistent with precedent of this Court. Consistent with
Madsen’s conclusion pertaining to the common-law nature of
military commissions and the President’s discretion to pre
scribe their procedures, Article 36 of the UCMJ authorizes
the President to establish procedures for military commis
sions “which shall, so far as he considers practicable, apply
the principles of law and the rules of evidence generally rec
ognized in the trial of criminal cases in the United States
district courts, but which may not be contrary to or incon
sistent with this chapter.” 10 U. S. C. § 836(a) (emphasis
added). Far from constraining the President’s authority,
Article 36 recognizes the President’s prerogative to depart
from the procedures applicable in criminal cases whenever
he alone does not deem such procedures “practicable.”
While the procedural regulations promulgated by the Execu
tive must not be “contrary to” the UCMJ, only a few provi
sions of the UCMJ mention “military commissions,” see ante,
at 621, n. 49, and there is no suggestion that the procedures
to be employed by Hamdan’s commission implicate any of
those provisions.
Notwithstanding the foregoing, the Court concludes that
Article 36(b) of the UCMJ, 10 U. S. C. § 836(b), which pro
vides that “[a]ll rules and regulations made under this article
shall be uniform insofar as practicable,” ante, at 620, requires
the President to employ the same rules and procedures in
military commissions as are employed by courts-martial
“ ‘insofar as practicable,’ ” ante, at 622. The Court fur
ther concludes that Hamdan’s commission is unlawful be
cause the President has not explained why it is not prac
ticable to apply the same rules and procedures to Hamdan’s
commission as would be applied in a trial by court-martial.
Ante, at 623–624.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
709 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
This interpretation of § 836(b) is unconvincing. As an ini
tial matter, the Court fails to account for our cases interpret
ing the predecessor to Article 21 of the UCMJ—Article 15
of the Articles of War—which provides crucial context that
bears directly on the proper interpretation of Article 36(b).
Article 15 of the Articles of War provided that:
“The provisions of these articles conferring jurisdiction
upon courts-martial shall not be construed as depriving
military commissions, provost courts, or other military
tribunals of concurrent jurisdiction in respect of offend
ers or offenses that by statute or by the law of war may
be triable by such military commissions, provost courts,
or other military tribunals.” 41 Stat. 790.
In Yamashita, this Court concluded that Article 15 of the
Articles of War preserved the President’s unfettered author
ity to prescribe military commission procedure. The Court
explained, “[b]y thus recognizing military commissions in
order to preserve their traditional jurisdiction over enemy
combatants unimpaired by the Articles, Congress gave
sanction . . . to any use of the military commission contem
plated by the common law of war.” 327 U. S., at 20 (empha
sis added);16 see also Quirin, 317 U. S., at 28; Madsen, 343
U. S., at 355. In reaching this conclusion, this Court treated
as authoritative the congressional testimony of Judge Advo
16 The Court suggests that Congress’ amendment to Article 2 of the
UCMJ, providing that the UCMJ applies to “persons within an area leased
by or otherwise reserved or acquired for the use of the United States,” 10
U. S. C. § 802(a)(12), deprives Yamashita’s conclusion respecting the Presi
dent’s authority to promulgate military commission procedures of its
“precedential value.” Ante, at 620. But this merely begs the question
of the scope and content of the remaining provisions of the UCMJ. Noth
ing in the additions to Article 2, or any other provision of the UCMJ,
suggests that Congress has disturbed this Court’s unequivocal interpreta
tion of Article 21 as preserving the common-law status of military commis
sions and the corresponding authority of the President to set their proce
dures pursuant to his Commander in Chief powers. See Quirin, 317 U. S.,
at 28; Yamashita, 327 U. S., at 20; Madsen v. Kinsella, 343 U. S. 341, 355
(1952).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
710 HAMDAN v. RUMSFELD
Thomas, J., dissenting
cate General Crowder, who testified that Article 15 of the
Articles of War was enacted to preserve the military com
mission as “ ‘our common-law war court.’ ” Yamashita,
supra, at 19, n. 7. And this Court recognized that Article
15’s preservation of military commissions as common-law
war courts preserved the President’s Commander in Chief
authority to both “establish” military commissions and to
“prescribe [their] procedure[s].” Madsen, 343 U. S., at 348;
id., at 348–349 (explaining that Congress had “refrain[ed]
from legislating” in the area of military commission proce
dures, in “contras[t] with its traditional readiness to . . . pre
scrib[e], with particularity, the jurisdiction and procedure of
United States courts-martial”); cf. Green 834 (“The military
commission exercising jurisdiction under common law au
thority is usually appointed by a superior military com
mander and is limited in its procedure only by the will of
that commander. Like any other common law court, in the
absence of directive of superior authority to the contrary,
the military commission is free to formulate its own rules
of procedure”).
Given these precedents, the Court’s conclusion that Article
36(b) requires the President to apply the same rules and pro
cedures to military commissions as are applicable to courts
martial is unsustainable. When Congress codified Article 15
of the Articles of War in Article 21 of the UCMJ it was “pre
sumed to be aware of . . . and to adopt” this Court’s interpre
tation of that provision as preserving the common-law status
of military commissions, inclusive of the President’s unfet
tered authority to prescribe their procedures. Lorillard v.
Pons, 434 U. S. 575, 580 (1978). The Court’s conclusion that
Article 36(b) repudiates this settled meaning of Article 21 is
not based upon a specific textual reference to military com
missions, but rather on a one-sentence subsection providing
that “[a]ll rules and regulations made under this article shall
be uniform insofar as practicable.” 10 U. S. C. § 836(b). This
is little more than an impermissible repeal by implication.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
711 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
See Branch v. Smith, 538 U. S. 254, 273 (2003) (plurality opin
ion) (“We have repeatedly stated . . . that absent a clearly
expressed congressional intention, repeals by implication are
not favored” (citations and internal quotation marks omit
ted)). Moreover, the Court’s conclusion is flatly contrary to
its duty not to set aside Hamdan’s commission “without the
clear conviction that [it is] in conflict with the . . . laws of
Congress constitutionally enacted.” Quirin, supra, at 25
(emphasis added).
Nothing in the text of Article 36(b) supports the Court’s
sweeping conclusion that it represents an unprecedented
congressional effort to change the nature of military commis
sions from common-law war courts to tribunals that must
presumptively function like courts-martial. And such an in
terpretation would be strange indeed. The vision of uni
formity that motivated the adoption of the UCMJ, embodied
specifically in Article 36(b), is nothing more than uniformity
across the separate branches of the armed services. See Act
of May 5, 1950, ch. 169, 64 Stat. 107 (preamble to the UCMJ
explaining that the UCMJ is an Act “[t]o unify, consolidate,
revise, and codify the Articles of War, the Articles for the
Government of the Navy, and the disciplinary laws of the
Coast Guard”). There is no indication that the UCMJ was
intended to require uniformity in procedure between courts
martial and military commissions, tribunals that the UCMJ
itself recognizes are different. To the contrary, the UCMJ
expressly recognizes that different tribunals will be consti
tuted in different manners and employ different procedures.
See 10 U. S. C. § 866 (providing for three different types of
courts-martial—general, special, and summary—constituted
in different manners and employing different procedures).
Thus, Article 36(b) is best understood as establishing that,
so far as practicable, the rules and regulations governing
tribunals convened by the Navy must be uniform with the
rules and regulations governing tribunals convened by the
Army. But, consistent with this Court’s prior interpreta

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
712 HAMDAN v. RUMSFELD
Thomas, J., dissenting
tions of Article 21 and over a century of historical practice,
it cannot be understood to require the President to conform
the procedures employed by military commissions to those
employed by courts-martial.17
Even if Article 36(b) could be construed to require proce
dural uniformity among the various tribunals contemplated
by the UCMJ, Hamdan would not be entitled to relief.
Under the Court’s reading, the President is entitled to pre
scribe different rules for military commissions than for
courts-martial when he determines that it is not “practica
ble” to prescribe uniform rules. The Court does not resolve
the level of deference such determinations would be owed,
however, because, in its view, “[t]he President has not . . .
[determined] that it is impracticable to apply the rules for
courts-martial.” Ante, at 623. This is simply not the case.
On the same day that the President issued Military Commis
sion Order No. 1, the Secretary of Defense explained that
“the president decided to establish military commissions be
cause he wanted the option of a process that is different from
those processes which we already have, namely, the federal
court system . . . and the military court system,” Dept. of
17 It bears noting that while the Court does not hesitate to cite legisla
tive history that supports its view of certain statutory provisions, see
ante, at 579, 580–581, n. 10, it makes no citation of the legislative history
pertaining to Article 36(b), which contradicts its interpretation of that
provision. Indeed, if it were authoritative, the only legislative history
relating to Article 36(b) would confirm the obvious—Article 36(b)’s uni
formity requirement pertains to uniformity between the three branches
of the Armed Forces, and no more. When that subsection was introduced
as an amendment to Article 36, its author explained that it would leave
the three branches “enough leeway to provide a different provision where
it is absolutely necessary” because “there are some differences in the serv
ices.” Hearings on H. R. 2498 before the Subcommittee No. 1 of the
House Committee on Armed Services, 81st Cong., 1st Sess., 1015 (1949).
A further statement explained that “there might be some slight differ
ences that would pertain as to the Navy in contrast to the Army, but at
least [Article 36(b)] is an expression of the congressional intent that we
want it to be as uniform as possible.” Ibid.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
713 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
Defense News Briefing on Military Commissions (Mar. 21,
2002) (remarks of Donald Rumsfeld), available at http://
www.dod.gov/transcripts/2002/t03212002_t0321sd.html (as
visited June 26, 2006, and available in Clerk of Court’s case
file) (hereinafter News Briefing), and that “[t]he commissions
are intended to be different . . . because the [P]resident rec
ognized that there had to be differences to deal with the
unusual situation we face and that a different approach was
needed.” Ibid. The President reached this conclusion
because
“we’re in the middle of a war, and . . . had to design a
procedure that would allow us to pursue justice for these
individuals while at the same time prosecuting the war
most effectively. And that means setting rules that
would allow us to preserve our intelligence secrets, de
velop more information about terrorist activities that
might be planned for the future so that we can take ac
tion to prevent terrorist attacks against the United
States. . . . [T]here was a constant balancing of the re
quirements of our war policy and the importance of pro
viding justice for the individuals . . . and each deviation
from the standard kinds of rules that we have in our
criminal courts was motivated by the desire to strike
this balance between individual justice and the broader
war policy.” Ibid. (remarks of Douglas J. Feith, Under
Secretary of Defense for Policy (emphasis added)).
The Court provides no explanation why the President’s de
termination that employing court-martial procedures in the
military commissions established pursuant to Military Com
mission Order No. 1 would hamper our war effort is in any
way inadequate to satisfy its newly minted “practicability”
requirement. On the contrary, this determination is pre
cisely the kind for which the “Judiciary has neither aptitude,
facilities nor responsibility and which has long been held to
belong in the domain of political power not subject to judicial

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
714 HAMDAN v. RUMSFELD
Thomas, J., dissenting
intrusion or inquiry.’ ” Chicago & Southern Air Lines, Inc.
v. Waterman S. S. Corp., 333 U. S., at 111. And, in the con
text of the present conflict, it is exactly the kind of determi
nation Congress countenanced when it authorized the Presi
dent to use all necessary and appropriate force against our
enemies. Accordingly, the President’s determination is suf
ficient to satisfy any practicability requirement imposed by
Article 36(b).
The Court further contends that Hamdan’s commission is
unlawful because it fails to provide him the right to be pres
ent at his trial, as recognized in 10 U. S. C. § 839(c) (2000 ed.,
Supp. V). Ante, at 624. But § 839(c) applies to courts
martial, not military commissions. It provides:
“When the members of a court-martial deliberate or
vote, only the members may be present. All other pro
ceedings, including any other consultation of the mem
bers of the court with counsel or the military judge,
shall be made a part of the record and shall be in the
presence of the accused, the defense counsel, the trial
counsel, and, in cases in which a military judge has been
detailed to the court, the military judge.”
In context, “all other proceedings” plainly refers exclusively
to “other proceedings” pertaining to a court-martial.18 This
is confirmed by the provision’s subsequent reference to
“members of the court” and to “cases in which a military
judge has been detailed to the court.” It is also confirmed
by the other provisions of § 839, which refer only to courts
martial. See §§ 839(a)(1)–(4) (“[A]ny time after the service
of charges which have been referred for trial to a court
martial composed of a military judge and members, the mili
18 In addition to being foreclosed by the text of the provision, the Court’s
suggestion that 10 U. S. C. § 839(c) (2000 ed., Supp. V) applies to military
commissions is untenable because it would require, in military commission
proceedings, that the accused be present when the members of the com
mission voted on his guilt or innocence.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
715 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
tary judge may . . . call the court into session without
the presence of the members for the purpose of ” hearing
motions, issuing rulings, holding arraignments, receiving
pleas, and performing various procedural functions). See
also § 839(b) (“Proceedings under subsection (a) shall be
conducted in the presence of the accused”). Section 839(c)
simply does not address the procedural requirements of
military commissions.
B
The Court contends that Hamdan’s military commission is
also unlawful because it violates Common Article 3 of the
Geneva Conventions, see ante, at 629–635. Furthermore,
Hamdan contends that his commission is unlawful because it
violates various provisions of the Third Geneva Convention.
These contentions are untenable.
1
As an initial matter, and as the Court of Appeals con
cluded, both of Hamdan’s Geneva Convention claims are fore
closed by Johnson v. Eisentrager, 339 U. S. 763 (1950). In
that case the respondents claimed, inter alia, that their mili
tary commission lacked jurisdiction because it failed to pro
vide them with certain procedural safeguards that they ar
gued were required under the Geneva Conventions. Id., at
789–790. While this Court rejected the underlying merits
of the respondents’ Geneva Convention claims, id., at 790, it
also held, in the alternative, that the respondents could “not
assert . . . that anything in the Geneva Convention makes
them immune from prosecution or punishment for war
crimes,” id., at 789. The Court explained:
“We are not holding that these prisoners have no right
which the military authorities are bound to respect.
The United States, by the Geneva Convention of July
27, 1929, 47 Stat. 2021, concluded with forty-six other
countries, including the German Reich, an agreement
upon the treatment to be accorded captives. These

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
716 HAMDAN v. RUMSFELD
Thomas, J., dissenting
prisoners claim to be and are entitled to its protection.
It is, however, the obvious scheme of the Agreement
that responsibility for observance and enforcement of
these rights is upon political and military authorities.
Rights of alien enemies are vindicated under it only
through protests and intervention of protecting powers
as the rights of our citizens against foreign governments
are vindicated only by Presidential intervention.” Id.,
at 789, n. 14.
This alternative holding is no less binding than if it were the
exclusive basis for the Court’s decision. See Massachusetts
v. United States, 333 U. S. 611, 623 (1948). While the Court
attempts to cast Eisentrager’s unqualified, alternative hold
ing as footnote dictum, ante, at 627, it does not dispute the
correctness of its conclusion, namely, that the provisions of
the 1929 Geneva Convention were not judicially enforceable
because that Convention contemplated that diplomatic meas
ures by political and military authorities were the exclusive
mechanisms for such enforcement. Nor does the Court sug
gest that the 1949 Geneva Conventions departed from this
framework. See ibid. (“We may assume that ‘the obvious
scheme’ of the 1949 Conventions is identical in all relevant
respects to that of the 1929 Convention”).
Instead, the Court concludes that petitioner may seek judi
cial enforcement of the provisions of the Geneva Conventions
because “they are . . . part of the law of war. And compli
ance with the law of war is the condition upon which the
authority set forth in Article 21 is granted.” Ante, at 628
(citation omitted). But Article 21 authorizes the use of mili
tary commissions; it does not purport to render judicially
enforceable aspects of the law of war that are not so enforce
able of their own accord. See Quirin, 317 U. S., at 28 (by
enacting Article 21, “Congress has explicitly provided, so far
as it may constitutionally do so, that military tribunals shall
have jurisdiction to try offenders or offenses against the law
of war”). The Court cannot escape Eisentrager’s holding

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
717 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
merely by observing that Article 21 mentions the law of war;
indeed, though Eisentrager did not specifically consider the
Court’s novel interpretation of Article 21, Eisentrager in
volved a challenge to the legality of a World War II military
commission, which, like all such commissions, found its au
thorization in Article 15 of the Articles of War, the predeces
sor to Article 21 of the UCMJ. Thus, the Court’s interpre
tation of Article 21 is foreclosed by Eisentrager.
In any event, the Court’s argument is too clever by half.
The judicial nonenforceability of the Geneva Conventions de
rives from the fact that those Conventions have exclusive
enforcement mechanisms, see Eisentrager, supra, at 789,
n. 14, and this, too, is part of the law of war. The Court’s
position thus rests on the assumption that Article 21’s refer
ence to the “laws of war” selectively incorporates only those
aspects of the Geneva Conventions that the Court finds con
venient, namely, the substantive requirements of Common
Article 3, and not those aspects of the Conventions that the
Court, for whatever reason, disfavors, namely, the Conven
tions’ exclusive diplomatic enforcement scheme. The Court
provides no account of why the partial incorporation of the
Geneva Conventions should extend only so far—and no fur
ther—because none is available beyond its evident prefer
ence to adjudicate those matters that the law of war, through
the Geneva Conventions, consigns exclusively to the politi
cal branches.
Even if the Court were correct that Article 21 of the
UCMJ renders judicially enforceable aspects of the law of
war that are not so enforceable by their own terms, Article
21 simply cannot be interpreted to render judicially enforce
able the particular provision of the law of war at issue here,
namely, Common Article 3 of the Geneva Conventions. As
relevant, Article 21 provides that “[t]he provisions of this
chapter conferring jurisdiction upon courts-martial do not
deprive military commissions . . . of concurrent jurisdiction
with respect to offenders or offenses that by statute or by

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
718 HAMDAN v. RUMSFELD
Thomas, J., dissenting
the law of war may be tried by military commissions.” 10
U. S. C. § 821 (emphasis added). Thus, to the extent Article
21 can be interpreted as authorizing judicial enforcement of
aspects of the law of war that are not otherwise judicially
enforceable, that authorization only extends to provisions of
the law of war that relate to whether a particular “offender”
or a particular “offense” is triable by military commission.
Common Article 3 of the Geneva Conventions, the sole provi
sion of the Geneva Conventions relevant to the Court’s hold
ing, relates to neither. Rather, it relates exclusively to the
particulars of the tribunal itself, namely, whether it is “regu
larly constituted” and whether it “afford[s] all the judicial
guarantees which are recognized as indispensable by civi
lized peoples.” Third Geneva Convention, Art. 3, ¶ 1(d),
Relative to the Treatment of Prisoners of War, Aug. 12, 1949,
[1955] 6 U. S. T. 3316, 3320, T. I. A. S. No. 3364.
2
In addition to being foreclosed by Eisentrager, Hamdan’s
claim under Common Article 3 of the Geneva Conventions is
meritless. Common Article 3 applies to “armed conflict not
of an international character occurring in the territory of
one of the High Contracting Parties.” 6 U. S. T., at 3318.
“Pursuant to [his] authority as Commander in Chief and
Chief Executive of the United States,” the President has “ac
cept[ed] the legal conclusion of the Department of Justice . . .
that common Article 3 of Geneva does not apply to . . . al
Qaeda . . . detainees, because, among other reasons, the rele
vant conflicts are international in scope and common Article
3 applies only to ‘armed conflict not of an international char
acter.’ ” App. 35. Under this Court’s precedents, “the
meaning attributed to treaty provisions by the Government
agencies charged with their negotiation and enforcement is
entitled to great weight.” Sumitomo Shoji America, Inc.
v. Avagliano, 457 U. S. 176, 184–185 (1982); United States v.
Stuart, 489 U. S. 353, 369 (1989). Our duty to defer to the

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
719 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
President’s understanding of the provision at issue here is
only heightened by the fact that he is acting pursuant to his
constitutional authority as Commander in Chief and by the
fact that the subject matter of Common Article 3 calls for a
judgment about the nature and character of an armed con
flict. See generally United States v. Curtiss-Wright Export
Corp., 299 U. S. 304, 320 (1936).
The President’s interpretation of Common Article 3 is rea
sonable and should be sustained. The conflict with al Qaeda
is international in character in the sense that it is occurring
in various nations around the globe. Thus, it is also “occur
ring in the territory of ” more than “one of the High Con
tracting Parties.” The Court does not dispute the Presi
dent’s judgments respecting the nature of our conflict with
al Qaeda, nor does it suggest that the President’s interpreta
tion of Common Article 3 is implausible or foreclosed by the
text of the treaty. Indeed, the Court concedes that Common
Article 3 is principally concerned with “furnish[ing] minimal
protection to rebels involved in . . . a civil war,” ante, at 631,
precisely the type of conflict the President’s interpretation
envisions to be subject to Common Article 3. Instead, the
Court, without acknowledging its duty to defer to the Presi
dent, adopts its own, admittedly plausible, reading of Com
mon Article 3. But where, as here, an ambiguous treaty
provision (“not of an international character”) is susceptible
of two plausible, and reasonable, interpretations, our prece
dents require us to defer to the Executive’s interpretation.
3
But even if Common Article 3 were judicially enforceable
and applicable to the present conflict, petitioner would not
be entitled to relief. As an initial matter, any claim peti
tioner has under Common Article 3 is not ripe. The only
relevant “acts” that “are and shall remain prohibited” under
Common Article 3 are “the passing of sentences and the car
rying out of executions without previous judgment pro

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
720 HAMDAN v. RUMSFELD
Thomas, J., dissenting
nounced by a regularly constituted court affording all the
judicial guarantees which are recognized as indispensable by
civilized peoples.” Art. 3, ¶ 1(d), 6 U. S. T., at 3318, 3320
(emphasis added). As its terms make clear, Common Article
3 is only violated, as relevant here, by the act of “passing of
sentenc[e],” and thus Hamdan will only have a claim if his
military commission convicts him and imposes a sentence.
Accordingly, as Hamdan’s claim is “contingent [upon] future
events that may not occur as anticipated, or indeed may not
occur at all,” it is not ripe for adjudication. Texas v. United
States, 523 U. S. 296, 300 (1998) (internal quotation marks
omitted).19 Indeed, even if we assume he will be convicted
and sentenced, whether his trial will be conducted in a man
ner so as to deprive him of “the judicial guarantees which
are recognized as indispensable by civilized peoples” is en
tirely speculative. And premature adjudication of Hamdan’s
claim is especially inappropriate here because “reaching the
merits of the dispute would force us to decide whether an
action taken by one of the other two branches of the Federal
Government was unconstitutional.” Raines v. Byrd, 521
U. S. 811, 819–820 (1997).
In any event, Hamdan’s military commission complies with
the requirements of Common Article 3. It is plainly “regu
larly constituted” because such commissions have been em
ployed throughout our history to try unlawful combatants
for crimes against the law of war. This Court has recounted
that history as follows:
19 The Court does not dispute the conclusion that Common Article 3
cannot be violated unless and until Hamdan is convicted and sentenced.
Instead, it contends that “the Geneva Conventions d[o] not direct an ac
cused to wait until sentence is imposed to challenge the legality of the
tribunal that is to try him.” Ante, at 626, n. 55. But the Geneva Conven
tions do not direct defendants to enforce their rights through litigation,
but through the Conventions’ exclusive diplomatic enforcement provisions.
Moreover, neither the Court’s observation respecting the Geneva Conven
tions nor its reference to the equitable doctrine of abstention bears on the
constitutional prohibition on adjudicating unripe claims.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
721 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
“ ‘By a practice dating from 1847 and renewed and firmly
established during the Civil War, military commissions
have become adopted as authorized tribunals in this
country in time of war. . . . Their competency has been
recognized not only in acts of Congress, but in executive
proclamations, in rulings of the courts, and in the opin
ions of the Attorneys General.’ ” Madsen, 343 U. S., at
346, n. 8.
Hamdan’s commission has been constituted in accordance
with these historical precedents. As I have previously ex
plained, the procedures to be employed by that commission,
and the Executive’s authority to alter those procedures, are
consistent with the practice of previous American military
commissions. See supra, at 706–712, and n. 15.
The Court concludes Hamdan’s commission fails to satisfy
the requirements of Common Article 3 not because it differs
from the practice of previous military commissions but be
cause it “deviate[s] from [the procedures] governing courts
martial.” Ante, at 634. But there is neither a statutory
nor historical requirement that military commissions con
form to the structure and practice of courts-martial. A mili
tary commission is a different tribunal, serving a different
function, and thus operates pursuant to different procedures.
The 150-year pedigree of the military commission is itself
sufficient to establish that such tribunals are “regularly con
stituted court[s].” Art. 3, ¶ 1(d), 6 U. S. T., at 3320.
Similarly, the procedures to be employed by Hamdan’s
commission afford “all the judicial guarantees which are rec
ognized as indispensable by civilized peoples.” Neither the
Court nor petitioner disputes the Government’s description
of those procedures.
“Petitioner is entitled to appointed military legal coun
sel, 32 C.F.R. 9.4(c)(2), and may retain a civilian attorney
(which he has done), 32 C.F.R. 9.4(c)(2)(iii)(B). Peti
tioner is entitled to the presumption of innocence, 32

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
722 HAMDAN v. RUMSFELD
Thomas, J., dissenting
C.F.R. 9.5(b), proof beyond a reasonable doubt, 32 C.F.R.
9.5(c), and the right to remain silent, 32 C.F.R. 9.5(f).
He may confront witnesses against him, 32 C.F.R. 9.5(i),
and may subpoena his own witnesses, if reasonably
available, 32 C.F.R. 9.5(h). Petitioner may personally
be present at every stage of the trial unless he engages
in disruptive conduct or the prosecution introduces clas
sified or otherwise protected information for which no
adequate substitute is available and whose admission
will not deprive him of a full and fair trial, 32 C.F.R.
9.5(k); Military Commission Order No. 1 (Dep’t of De
fense Aug. 31, 2005) § 6(B)(3) and (D)(5)(b). If petitioner
is found guilty, the judgment will be reviewed by a re
view panel, the Secretary of Defense, and the President,
if he does not designate the Secretary as the final deci
sionmaker. 32 C.F.R. 9.6(h). The final judgment is
subject to review in the Court of Appeals for the Dis
trict of Columbia Circuit and ultimately in this Court.
See DTA § 1005(e)(3), 119 Stat. 2743; 28 U. S. C. 1254(1).”
Brief for Respondents 4.
Notwithstanding these provisions, which in my judgment
easily satisfy the nebulous standards of Common Article 3,20
the plurality concludes that Hamdan’s commission is unlaw
ful because of the possibility that Hamdan will be barred
from proceedings and denied access to evidence that may
be used to convict him. Ante, at 633–635. But, under the
commissions’ rules, the Government may not impose such
bar or denial on Hamdan if it would render his trial unfair,
20 Notably, a prosecutor before the Quirin military commission has de
scribed these procedures as “a substantial improvement over those in ef
fect during World War II,” further observing that “[t]hey go a long way
toward assuring that the trials will be full and fair.” National Institute of
Military Justice, Procedures for Trials by Military Commissions of Certain
Non-United States Citizens in the War Against Terrorism, p. x (2002)
(foreword by Lloyd N. Cutler).

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
723 Cite as: 548 U. S. 557 (2006)
Thomas, J., dissenting
a question that is clearly within the scope of the appellate
review contemplated by regulation and statute.
Moreover, while the Executive is surely not required to
offer a particularized defense of these procedures prior to
their application, the procedures themselves make clear that
Hamdan would only be excluded (other than for disruption)
if it were necessary to protect classified (or classifiable) intel
ligence, Dept. of Defense, Military Commission Order No. 1,
§ 6(B)(3) (Aug. 31, 2005), including the sources and methods
for gathering such intelligence. The Government has ex
plained that “we want to make sure that these proceedings,
which are going on in the middle of the war, do not interfere
with our war effort and . . . because of the way we would be
able to handle interrogations and intelligence information,
may actually assist us in promoting our war aims.” News
Briefing (remarks of Douglas J. Feith, Under Secretary of
Defense for Policy). And this Court has concluded, in the
very context of a threat to reveal our Nation’s intelligence
gathering sources and methods, that “[i]t is ‘obvious and un
arguable’ that no governmental interest is more compelling
than the security of the Nation,” Haig, 453 U. S., at 307
(quoting Aptheker v. Secretary of State, 378 U. S. 500, 509
(1964)), and that “[m]easures to protect the secrecy of our
Government’s foreign intelligence operations plainly serve
these interests,” Haig, supra, at 307. See also Snepp v.
United States, 444 U. S. 507, 509, n. 3 (1980) (per curiam)
(“The Government has a compelling interest in protecting
both the secrecy of information important to our national
security and the appearance of confidentiality so essential to
the effective operation of our foreign intelligence service”);
Curtiss-Wright, 299 U. S., at 320. This interest is surely
compelling here. According to the Government, “[b]ecause
al Qaeda operates as a clandestine force relying on sleeper
agents to mount surprise attacks, one of the most critical
fronts in the current war involves gathering intelligence
about future terrorist attacks and how the terrorist network

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
724 HAMDAN v. RUMSFELD
Thomas, J., dissenting
operates—identifying where its operatives are, how it plans
attacks, who directs operations, and how they communicate.”
Brief for United States in No. 03–4792, United States v.
Moussaoui (CA4), p. 9. We should not rule out the possibil
ity that this compelling interest can be protected, while at
the same time affording Hamdan (and others like him) a
fair trial.
In these circumstances, “civilized peoples” would take into
account the context of military commission trials against un
lawful combatants in the war on terrorism, including the
need to keep certain information secret in the interest of
preventing future attacks on our Nation and its foreign in
stallations so long as it did not deprive the accused of a fair
trial. Accordingly, the President’s understanding of the re
quirements of Common Article 3 is entitled to “great
weight.” See supra, at 718.
4
In addition to Common Article 3, which applies to conflicts
“not of an international character,” Hamdan also claims that
he is entitled to the protections of the Third Geneva Conven
tion, which applies to conflicts between two or more High
Contracting Parties. There is no merit to Hamdan’s claim.
Article 2 of the Convention provides that “the present
Convention shall apply to all cases of declared war or of any
other armed conflict which may arise between two or more
of the High Contracting Parties.” 6 U. S. T., at 3318. “Pur
suant to [his] authority as Commander in Chief and Chief
Executive of the United States,” the President has deter
mined that the Convention is inapplicable here, explaining
that “none of the provisions of Geneva apply to our conflict
with al Qaeda in Afghanistan or elsewhere throughout the
world because, among other reasons, al Qaeda is not a High
Contracting Party.” App. 35. The President’s findings
about the nature of the present conflict with respect to mem
bers of al Qaeda operating in Afghanistan represents a core

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
Cite as: 548 U. S. 557 (2006) 725
Alito, J., dissenting
exercise of his Commander in Chief authority that this Court
is bound to respect. See Prize Cases, 2 Black, at 670.
* * *
For these reasons, I would affirm the judgment of the
Court of Appeals.
Justice Alito, with whom Justice Scalia and Justice
Thomas join in Parts I–III, dissenting.
For the reasons set out in Justice Scalia’s dissent, which
I join, I would hold that we lack jurisdiction. On the merits,
I join Justice Thomas’ dissent with the exception of
Parts I, II–C–1, and III–B–2, which concern matters that I
find unnecessary to reach. I add the following comments to
provide a further explanation of my reasons for disagreeing
with the holding of the Court.
I
The holding of the Court, as I understand it, rests on the
following reasoning. A military commission is lawful only if
it is authorized by 10 U. S. C. § 821; this provision permits
the use of a commission to try “offenders or offenses” that
“by statute or by the law of war may be tried by” such a
commission; because no statute provides that an offender
such as petitioner or an offense such as the one with which
he is charged may be tried by a military commission, he may
be tried by military commission only if the trial is authorized
by “the law of war”; the Geneva Conventions are part of the
law of war; and Common Article 3 of the Conventions prohib
its petitioner’s trial because the commission before which he
would be tried is not “a regularly constituted court,” Third
Geneva Convention, Art. 3, ¶ 1(d), Relative to the Treatment
of Prisoners of War, Aug. 12, 1949, [1955] 6 U. S. T. 3316,
3320, T. I. A. S. No. 3364. I disagree with this holding
because petitioner’s commission is “a regularly constituted
court.”

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
726 HAMDAN v. RUMSFELD
Alito, J., dissenting
Common Article 3 provides as follows:
“In the case of armed conflict not of an international
character occurring in the territory of one of the High
Contracting Parties, each Party to the conflict shall be
bound to apply, as a minimum, the following provisions:
“(1) . . . [T]he following acts are and shall remain
prohibited . . . :
. . . . .
“(d) [T]he passing of sentences and the carrying out
of executions without previous judgment pronounced by
a regularly constituted court affording all the judicial
guarantees which are recognized as indispensable by
civilized peoples.” Id., at 3318–3320 (emphasis added).
Common Article 3 thus imposes three requirements. Sen
tences may be imposed only by (1) a “court” (2) that is “regu
larly constituted” and (3) that affords “all the judicial guar
antees which are recognized as indispensable by civilized
peoples.” Id., at 3320.
I see no need here to comment extensively on the meaning
of the first and third requirements. The first requirement
is largely self-explanatory, and, with respect to the third,
I note only that on its face it imposes a uniform international
standard that does not vary from signatory to signatory.
The second element (“regularly constituted”) is the one on
which the Court relies, and I interpret this element to re
quire that the court be appointed or established in accord
ance with the appointing country’s domestic law. I agree
with the Court, see ante, at 632, n. 64, that, as used in Com
mon Article 3, the term “regularly” is synonymous with
“properly.” The term “constitute” means “appoint,” “set
up,” or “establish,” Webster’s Third New International Dic
tionary 486 (1961), and therefore “regularly constituted”
means properly appointed, set up, or established. Our cases
repeatedly use the phrases “regularly constituted” and
“properly constituted” in this sense. See, e. g., Hamdi v.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
727 Cite as: 548 U. S. 557 (2006)
Alito, J., dissenting
Rumsfeld, 542 U. S. 507, 538 (2004) (plurality opinion of
O’Connor, J.); Nguyen v. United States, 539 U. S. 69, 83
(2003); Ryder v. United States, 515 U. S. 177, 187 (1995); Wil
liams v. Bruffy, 96 U. S. 176, 185 (1878).
In order to determine whether a court has been properly
appointed, set up, or established, it is necessary to refer to a
body of law that governs such matters. I interpret Common
Article 3 as looking to the domestic law of the appointing
country because I am not aware of any international law
standard regarding the way in which such a court must be
appointed, set up, or established, and because different coun
tries with different government structures handle this mat
ter differently. Accordingly, “a regularly constituted court”
is a court that has been appointed, set up, or established in
accordance with the domestic law of the appointing country.
II
In contrast to this interpretation, the opinions supporting
the judgment today hold that the military commission before
which petitioner would be tried is not “a regularly consti
tuted court” (1) because “no evident practical need explains”
why its “structure and composition . . . deviate from conven
tional court-martial standards,” ante, at 647 (Kennedy, J.,
concurring in part); see also ante, at 632–633 (opinion of the
Court); and (2) because, contrary to 10 U. S. C. § 836(b), the
procedures specified for use in the proceeding before the mil
itary commission impermissibly differ from those provided
under the Uniform Code of Military Justice (UCMJ) for use
by courts-martial, ante, at 615–625 (opinion of the Court);
ante, at 651–653 (Kennedy, J., concurring in part). I do not
believe that either of these grounds is sound.
A
I see no basis for the Court’s holding that a military com
mission cannot be regarded as “a regularly constituted
court” unless it is similar in structure and composition to a

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
728 HAMDAN v. RUMSFELD
Alito, J., dissenting
regular military court or unless there is an “evident practical
need” for the divergence. There is no reason why a court
that differs in structure or composition from an ordinary mil
itary court must be viewed as having been improperly con
stituted. Tribunals that vary significantly in structure,
composition, and procedures may all be “regularly” or “prop
erly” constituted. Consider, for example, a municipal court,
a state trial court of general jurisdiction, an Article I federal
trial court, a federal district court, and an international
court, such as the International Criminal Tribunal for the
former Yugoslavia. Although these courts are “differently
constituted” and differ substantially in many other respects,
they are all “regularly constituted.”
If Common Article 3 had been meant to require trial be
fore a country’s military courts or courts that are similar in
structure and composition, the drafters almost certainly
would have used language that expresses that thought more
directly. Other provisions of the Convention Relative to the
Treatment of Prisoners of War refer expressly to the ordi
nary military courts and expressly prescribe the “uniformity
principle” that Justice Kennedy sees in Common Article
3, see ante, at 643–644. Article 84 provides that “[a] pris
oner of war shall be tried only by a military court, unless the
existing laws of the Detaining Power expressly permit the
civil courts to try a member of the armed forces of the De
taining Power in respect of the particular offence alleged to
have been committed by the prisoner of war.” 6 U. S. T., at
3382. Article 87 states that “[p]risoners of war may not be
sentenced by the military authorities and courts of the De
taining Power to any penalties except those provided for in
respect of members of the armed forces of the said Power
who have committed the same acts.” Id., at 3384. Simi
larly, Article 66 of the Geneva Convention Relative to the
Protection of Civilian Persons in Time of War—a provision
to which the Court looks for guidance in interpreting Com
mon Article 3, see ante, at 632—expressly provides that ci

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
729 Cite as: 548 U. S. 557 (2006)
Alito, J., dissenting
vilians charged with committing crimes in occupied territory
may be handed over by the occupying power “to its properly
constituted, non-political military courts, on condition that
the said courts sit in the occupied country.” 6 U. S. T. 3516,
3558–3560, T. I. A. S. No. 3365. If Common Article 3 had
been meant to incorporate a “uniformity principle,” it pre
sumably would have used language like that employed in
the provisions noted above. For these reasons, I cannot
agree with the Court’s conclusion that the military commis
sion at issue here is not a “regularly constituted court” be
cause its structure and composition differ from those of a
court-martial.
Contrary to the suggestion of the Court, see ante, at 632,
the commentary on Article 66 of the Fourth Geneva Conven
tion does not undermine this conclusion. As noted, Article
66 permits an occupying power to try civilians in its “prop
erly constituted, non-political military courts,” 6 U. S. T., at
3558. The commentary on this provision states:
“The courts are to be ‘regularly constituted.’ This
wording definitely excludes all special tribunals. It is
the ordinary military courts of the Occupying Power
which will be competent.” 4 Int’l Comm. of Red Cross,
Commentary: Geneva Convention Relative to the Pro
tection of Civilian Persons in Time of War 340 (J. Pictet
gen. ed. 1958) (hereinafter GCIV Commentary).
The Court states that this commentary “defines ‘ “regu
larly constituted” ’ tribunals to include ‘ordinary military
courts’ and ‘definitely exclud[e] all special tribunals.’ ”
Ante, at 632 (alteration in original). This much is clear from
the commentary itself. Yet the mere statement that a mili
tary court is a regularly constituted tribunal is of no help in
addressing petitioner’s claim that his commission is not such
a tribunal. As for the commentary’s mention of “special tri
bunals,” it is doubtful whether we should take this gloss on
Article 66—which prohibits an occupying power from trying
civilians in courts set up specially for that purpose—to tell

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
730 HAMDAN v. RUMSFELD
Alito, J., dissenting
us much about the very different context addressed by Com
mon Article 3.
But even if Common Article 3 recognizes this prohibition
on “special tribunals,” that prohibition does not cover peti
tioner’s tribunal. If “special” means anything in contradis
tinction to “regular,” it would be in the sense of “special” as
“relating to a single thing,” and “regular” as “uniform in
course, practice, or occurrence.” Webster’s Third New In
ternational Dictionary 2186, 1913. Insofar as respondents
propose to conduct the tribunals according to the procedures
of Military Commission Order No. 1 and orders promulgated
thereunder—and nobody has suggested respondents intend
otherwise—then it seems that petitioner’s tribunal, like the
hundreds of others respondents propose to conduct, is very
much regular and not at all special.
B
I also disagree with the Court’s conclusion that petitioner’s
military commission is “illegal,” ante, at 625, because its pro
cedures allegedly do not comply with 10 U. S. C. § 836. Even
if § 836(b), unlike Common Article 3, does impose at least a
limited uniformity requirement amongst the tribunals con
templated by the UCMJ, but see ante, at 711–712 (Thomas,
J., dissenting), and even if it is assumed for the sake of ar
gument that some of the procedures specified in Military
Commission Order No. 1 impermissibly deviate from court
martial procedures, it does not follow that the military
commissions created by that order are not “regularly consti
tuted” or that trying petitioner before such a commission
would be inconsistent with the law of war. If Congress
enacted a statute requiring the federal district courts to fol
low a procedure that is unconstitutional, the statute would
be invalid, but the district courts would not. Likewise, if
some of the procedures that may be used in military commis
sion proceedings are improper, the appropriate remedy is to
proscribe the use of those particular procedures, not to out

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
731 Cite as: 548 U. S. 557 (2006)
Alito, J., dissenting
law the commissions. I see no justification for striking
down the entire commission structure simply because it is
possible that petitioner’s trial might involve the use of some
procedure that is improper.
III
Returning to the three elements of Common Article 3—
(1) a court, (2) that is appointed, set up, and established in
compliance with domestic law, and (3) that respects univer
sally recognized fundamental rights—I conclude that all of
these elements are satisfied in this case.
A
First, the commissions qualify as courts.
Second, the commissions were appointed, set up, and es
tablished pursuant to an order of the President, just like the
commission in Ex parte Quirin, 317 U. S. 1 (1942), and the
Court acknowledges that Quirin recognized that the statu
tory predecessor of 10 U. S. C. § 821 “preserved” the Presi
dent’s power “to convene military commissions,” ante, at 593.
Although Justice Kennedy concludes that “an acceptable
degree of independence from the Executive is necessary to
render a commission ‘regularly constituted’ by the standards
of our Nation’s system of justice,” ante, at 645, he offers no
support for this proposition (which in any event seems to
be more about fairness or integrity than regularity). The
commission in Quirin was certainly no more independent
from the Executive than the commissions at issue here, and
10 U. S. C. §§ 821 and 836 do not speak to this issue.1
Finally, the commission procedures, taken as a whole, and
including the availability of review by a United States Court
of Appeals and by this Court, do not provide a basis for
1 Section 821 looks to the “law of war,” not separation-of-powers issues.
And § 836, as Justice Kennedy notes, concerns procedures, not struc
ture, see ante, at 645.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
732 HAMDAN v. RUMSFELD
Alito, J., dissenting
deeming the commissions to be illegitimate. The Court
questions the following two procedural rules: the rule allow
ing the Secretary of Defense to change the governing rules
“ ‘from time to time’ ” (which does not rule out midtrial
changes), see ante, at 633, n. 65 (opinion of the Court); ante,
at 645 (Kennedy, J., concurring in part), and the rule that
permits the admission of any evidence that would have
“ ‘probative value to a reasonable person’ ” (which departs
from our legal system’s usual rules of evidence), see ante, at
614–615, 623 (opinion of the Court); ante, at 651–653 (Ken
nedy, J., concurring in part).2 Neither of these two rules
undermines the legitimacy of the commissions.
Surely the entire commission structure cannot be stricken
merely because it is possible that the governing rules might
be changed during the course of one or more proceedings.
If a change is made and applied during the course of an ongo
ing proceeding and if the accused is found guilty, the validity
of that procedure can be considered in the review proceeding
for that case. After all, not every midtrial change will be
prejudicial. A midtrial change might amend the governing
rules in a way that is inconsequential or actually favorable
to the accused.
As for the standard for the admission of evidence at com
mission proceedings, the Court does not suggest that this
rule violates the international standard incorporated into
Common Article 3 (“the judicial guarantees which are recog
nized as indispensable by civilized peoples,” 6 U. S. T., at
3320). Rules of evidence differ from country to country, and
much of the world does not follow aspects of our evidence
2 The plurality, but not Justice Kennedy, suggests that the commission
rules are improper insofar as they allow a defendant to be denied access
to evidence under some circumstances. See ante, at 633–635. But here,
too, if this procedure is used in a particular case and the accused is con
victed, the validity of this procedure can be challenged in the review pro
ceeding in that case. In that context, both the asserted need for the pro
cedure and its impact on the accused can be analyzed in concrete terms.

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
733 Cite as: 548 U. S. 557 (2006)
Alito, J., dissenting
rules, such as the general prohibition against the admission
of hearsay. See, e. g., Blumenthal, Shedding Some Light on
Calls for Hearsay Reform: Civil Law Hearsay Rules in His
torical and Modern Perspective, 13 Pace Int’l L. Rev. 93, 96–
101 (2001). If a particular accused claims to have been un
fairly prejudiced by the admission of particular evidence,
that claim can be reviewed in the review proceeding for that
case. It makes no sense to strike down the entire commis
sion structure based on speculation that some evidence
might be improperly admitted in some future case.
In sum, I believe that Common Article 3 is satisfied here
because the military commissions (1) qualify as courts,
(2) that were appointed and established in accordance with
domestic law, and (3) any procedural improprieties that
might occur in particular cases can be reviewed in those
cases.
B
The commentary on Common Article 3 supports this inter
pretation. The commentary on Common Article 3, ¶ 1(d), in
its entirety states:
“[A]lthough [sentences and executions without a proper
trial] were common practice until quite recently, they
are nevertheless shocking to the civilized mind. . . .
Sentences and executions without previous trial are too
open to error. ‘Summary justice’ may be effective on
account of the fear it arouses . . . , but it adds too many
further innocent victims to all the other innocent victims
of the conflict. All civilized nations surround the ad
ministration of justice with safeguards aimed at elimi
nating the possibility of judicial errors. The Conven
tion has rightly proclaimed that it is essential to do this
even in time of war. We must be very clear about one
point: it is only ‘summary’ justice which it is intended
to prohibit. No sort of immunity is given to anyone
under this provision. There is nothing in it to prevent

548US2 Unit: $U86 [08-05-09 16:48:47] PAGES PGT: OPIN
734 HAMDAN v. RUMSFELD
Alito, J., dissenting
a person presumed to be guilty from being arrested and
so placed in a position where he can do no further harm;
and it leaves intact the right of the State to prosecute,
sentence and punish according to the law.” GCIV Com
mentary 39 (emphasis added).
It seems clear that the commissions at issue here meet this
standard. Whatever else may be said about the system that
was created by Military Commission Order No. 1 and aug
mented by the Detainee Treatment Act, § 1005(e)(1), 119
Stat. 2742, this system—which features formal trial proce
dures, multiple levels of administrative review, and the op
portunity for review by a United States Court of Appeals
and by this Court—does not dispense “summary justice.”
* * *
For these reasons, I respectfully dissent.