HAMDAN v

HAMDAN v. RUMSFELD (2006)

Justice Stevens, for the Court

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 Taliba, Hamdan was captured by Northern Alliance 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."

Hamdan filed petitions for writs of habeas corpus and mandamus 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 would have authority to try him. His objection is that the military commission the President has convened lacks such authority, for two principal reasons: First, neither congressional Act nor the common law of war supports 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 tenets of military and international law, including the principle that a defendant must be permitted to see and hear the evidence against him….

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 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."

On September 11, 2001, agents of the al Qaeda terrorist organization hijacked commercial airplanes and attacked the World Trade Center in New York City and the national headquarters of the Department of Defense in Arlington, Virginia. Americans will never forget the devastation wrought by these acts. Nearly 3,000 civilians were killed.

Congress responded by adopting a 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 terrorist attacks ... in order to prevent any future acts of international terrorism against the United States by such nations, organizations or persons." Acting pursuant to the AUMF, and having determined that the Taliban regime 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." 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. Any such individual "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 imprisonment or death….

On July 3, 2003, the President announced his determination 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 counsel was appointed to represent Hamdan. Two months later, counsel filed demands for charges and for a speedy trial pursuant to Article 10 of the UCMJ. On February 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 Washington, 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…charges that "from on or about February 1996 to on or about November 24, 2001," Hamdan "willfully and knowingly joined an enterprise of persons who shared a common criminal purpose and conspired and agreed with [named members of al Qaeda] to commit the following offenses triable by military commission: attacking civilians; attacking civilian objects; murder by an unprivileged belligerent; and terrorism." There is no allegation that Hamdan had any command responsibilities, played a leadership role, or participated in the planning of any activity….

IV.

The military commission, a tribunal neither mentioned in the Constitution nor created by statute, was born of military necessity….

Exigency alone, of course, will not justify the establishment 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, see also Quirin. And that authority, if it exists, can derive only from the powers granted jointly to the President and Congress in time of war. In re Yamashita.

The Constitution makes the President the "Commander in Chief" of the Armed Forces, but vests in Congress the powers to "declare War ... and make Rules concerning Captures on Land and Water," to "raise and support Armies," to "define and punish ... Offences against the Law of Nations," "To make Rules for the Government and Regulation of the land and naval Forces," 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 peace, intrude upon the proper authority of Congress, nor Congress upon the proper authority 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 insures acts of indemnity from the justice of the legislature."

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 answered 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 circumstances. 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, reads as follows:

"The provisions of this code 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 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."

We have no occasion to revisit Quirin's controversial characterization of Article of War 15 as congressional authorization for military commissions. 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 necessary…."

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 President's authority to convene military commissions. First, while we assume that the AUMF activated the President's war powers, see Hamdi v. Rumsfeld, and that those powers include the authority to convene military commissions in appropriate circumstances, there is nothing in the text or legislative history of the AUMF even hinting that Congress intended to expand or alter the authorization set forth in Article 21 of the UCMJ….

Together, the UCMJ, the AUMF…at most acknowledge a general Presidential authority to convene military 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.

VI.

Whether or not the Government has charged Hamdan with an offense against the law of war cognizable by military commission, 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,”--including the four Geneva Conventions signed in 1949. The procedures that the Government has decreed will govern Hamdan's trial by commission violate these laws.

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 members, all of whom must be commissioned officers. The presiding officer's job is to rule on questions of law and other evidentiary and interlocutory issues; the other members make findings and, if applicable, sentencing decisions. 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."

The accused also is entitled to a copy of the charge(s) against him, both in English and his own language (if different), to a presumption of innocence, and to certain other rights typically afforded criminal defendants in civilian courts and courts-martial. These rights 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 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 his or her client what took place therein.

Another striking feature of the rules governing Hamdan's commission is that they permit the admission of any evidence that, in the opinion of the presiding officer, "would have probative value to a reasonable person." 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. Moreover, the accused and his civilian counsel may be denied access to evidence in the form of "protected information" (which includes classified information as well as "information protected by law or rule from unauthorized disclosure" and "information concerning other national security interests," so long as the presiding officer concludes 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." Finally, a presiding officer's determination that evidence "would not have probative value to a reasonable person" may be overridden by a majority of the other commission members.

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). Any appeal is taken to a three-member review panel composed of military officers and designated by the Secretary of Defense, only one member of which need have experience as a judge. The review panel is directed to "disregard any variance from procedures specified in this Order or elsewhere that would not materially have affected the outcome of the trial before the Commission." 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 recommendation as to final disposition. The President then, unless he has delegated the task to the Secretary, makes the "final decision." He may change the commission's findings or sentence only in a manner favorable to the accused.

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 commission illegal. Chief among his particular objections are that he may, under the Commission Order, be convicted based on evidence he has not seen or heard, and that any evidence admitted against him need not comply with the admissibility or relevance rules typically applicable in criminal trials and court-martial proceedings…We turn, then, to consider the merits of Hamdan's procedural challenge.

In part because the difference between military commissions and courts-martial originally was a difference of jurisdiction 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…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.

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 significant respects from those then governing courts-martial….

The procedures and rules of evidence employed during Yamashita'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. Among the dissenters' primary concerns was that the commission had free rein to consider all evidence "which in the commission's opinion 'would be of assistance in proving or disproving the charge,' without any of the usual modes of authentication."

The majority, however, did not pass on the merits of Yamashita's procedural challenges…At least partially in response to subsequent criticism of General Yamashita's trial, the UCMJ's codification of the Articles of War after World War II expanded the category of persons subject thereto to include defendants in Yamashita's (and Hamdan's) position, and the Third Geneva Convention of 1949 extended prisoner-of-war protections to individuals tried for crimes committed before their capture. 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….

Article 36 places two restrictions on the President's power to promulgate rules of procedure for courts-martial and military commissions alike. First, no procedural rule he adopts may be "contrary to or inconsistent with" the UCMJ--however practical it may seem. Second, the rules adopted must be "uniform insofar as practicable." That is, the rules applied to military commissions must be the same as those applied to courts-martial unless such uniformity proves impracticable.

Hamdan argues that Commission Order No. 1 violates both of these restrictions; he maintains that the procedures described 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.) 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." Hamdan also observes that the Commission Order dispenses with virtually all evidentiary rules applicable in courts-martial.

The Government has three responses…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 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.

Hamdan has the better of this argument. Without reaching the question whether any provision of Commission Order No. 1 is strictly "contrary to or inconsistent with" other provisions of the UCMJ, we conclude that the "practicability" determination the President has made is insufficient to justify variances from the procedures governing courts-martial….

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 difficulty in securing properly sworn and authenticated evidence or in applying the usual principles of relevance and admissibility. Assuming arguendo that the reasons articulated in the President's Article 36(a) determination ought to be considered in evaluating the impracticability of applying court-martial rules, the only reason offered in support of that determination is the danger posed by international terrorism. 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 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. Whether or not that departure technically is "contrary to or inconsistent with" the terms of the UCMJ, 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 Commission Order No. 1 deviates in many significant respects from those rules, it necessarily violates Article 36(b)….

The procedures adopted to try Hamdan also violate the Geneva Conventions. The Court of Appeals dismissed Hamdan's Geneva Convention challenge on three independent grounds: (1) the Geneva Conventions are not judicially enforceable; (2) Hamdan in any event is not entitled to their protections…for the reasons that follow, we hold that neither of the other grounds the Court of Appeals gave for its decision is persuasive.

We may assume that "the obvious scheme" of the 1949 Conventions is identical in all relevant respects to that of the 1929 Convention, and even that that scheme would, absent some other provision of law, preclude Hamdan's invocation of the Convention's provisions as an independent source of law binding the Government's actions and furnishing petitioner with any enforceable right. For, regardless of the nature of the rights conferred on Hamdan, they are, as the Government does not dispute, part of the law of war….

For the Court of Appeals, acknowledgment of that condition 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 accepted 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. We…disagree with the latter conclusion.

The conflict with al Qaeda is not, according to the Government, a conflict to which the full protections afforded detainees 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 Contracting Parties." Since Hamdan was captured 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 signatory of the Conventions, the protections of those Conventions are not, it is argued, applicable to Hamdan.

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 between signatories. 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 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," certain provisions protecting "[p]ersons taking no active part in the hostilities, including members of armed forces who have laid down their arms and those placed hors de combat by ... detention." One such provision prohibits "the 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."

The Court of Appeals thought, and the Government asserts, that Common Article 3 does not apply to Hamdan because the conflict with al Qaeda, being " 'international in scope,' " does not qualify as a " 'conflict not of an international character.' That reasoning is erroneous. The term "conflict not of an international character" is used here in contradistinction to a conflict between nations. So much is demonstrated by the "fundamental logic [of] the Convention's provisions on its application." Common Article 2 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." High Contracting Parties (signatories) also must abide by all terms of the Conventions vis-À-vis one another even if one party to the conflict is a nonsignatory "Power," and must so abide vis-À-vis the nonsignatory if "the latter 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 "Power" who are involved in a conflict "in the territory of" a signatory. The latter kind of conflict is distinguishable from the conflict described in Common Article 2 chiefly because it does not involve a clash between nations (whether signatories or not). In context, then, the phrase "not of an international character" bears its literal meaning….

iii

Common Article 3, then, is applicable here and, as indicated above, requires that Hamdan be tried by a "regularly constituted court affording all the judicial guarantees which are recognized as indispensable by civilized peoples." While the term "regularly constituted court" is not specifically defined in either Common Article 3 or its accompanying commentary, other sources disclose its core meaning. The commentary accompanying a provision of the Fourth Geneva Convention, for example, defines " 'regularly constituted' " tribunals to include "ordinary military courts" and "definitely exclud[e] all special tribunals…."

The Government offers only a cursory defense of Hamdan's military commission in light of Common Article 3. As Justice Kennedy explains, that defense fails because "[t]he regular military courts in our system are the courts-martial established by congressional statutes." At a minimum, a military commission "can be 'regularly constituted' by the standards of our military justice system only if some practical need explains deviations from court-martial practice." As we have explained, no such need has been demonstrated here.

Inextricably intertwined with the question of regular constitution 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." Like the phrase "regularly 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…Among the rights set forth in Article 75 is the "right to be tried in [one's] presence."

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," and for that reason, at least, fail to afford the requisite guarantees. We add only that, as noted, various provisions of Commission Order No. 1 dispense with the principles, articulated 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. That the Government has a compelling interest in denying Hamdan access to certain sensitive information is not doubted. But, at least absent express statutory provision to the contrary, information used to convict a person of a crime must be disclosed to him.

Common Article 3 obviously tolerates a great degree of flexibility in trying individuals captured during armed conflict; its requirements are general ones, crafted to accommodate a wide variety of legal systems. But requirements they are nonetheless. The commission that the President 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 address, the Government's power to detain him for the duration 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.

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." They suggest that it undermines our Nation's ability to "preven[t] future attacks" of the grievous sort that we have already suffered. 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 ultimately rests upon a single ground: Congress has not issued the Executive a "blank check." Cf. Hamdi v. Rumsfeld. 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 contrary, that insistence strengthens the Nation's ability to determine--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 military 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 authority 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 independent branch of government, and as part of a long tradition 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 requirements 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 reliance on standards tested over time and insulated from the pressures of the moment….

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. 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 tribunals are established, full and proper authority exists for the Presidential directive.

The proper framework for assessing whether Executive actions are authorized is the three-part scheme used by Justice Jackson in his opinion in Youngstown Sheet & Tube Co. v. Sawyer, (1952). "When the President acts pursuant to an express or implied authorization of Congress, his authority is at its maximum, for it includes all that he possesses in his own right plus all that Congress can delegate." "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 twilight in which he and Congress may have concurrent authority, or in which its distribution is uncertain." And "[w]hen the President takes measures incompatible with the expressed or implied will of Congress, his power is at its lowest ebb."

In this case, as the Court observes, the President has acted in a field with a history of congressional participation and regulation. In the Uniform Code of Military Justice (UCMJ), which Congress enacted, building on earlier statutes…Congress has set forth governing principles for military courts. The UCMJ as a whole establishes an intricate system of military justice….As explained below, the statute further recognizes that special military commissions may be convened to try war crimes. 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 Presidential and congressional action--a case within Justice Jackson's third category, not the second or first.

One limit on the President's authority is contained in §836 of the UCMJ. That section provides:

(a) Pretrial, trial, and post-trial procedures, including modes of proof, for cases arising under this chapter triable 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 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."

In this provision the statute allows the President to implement and build on the UCMJ's framework by adopting procedural regulations, subject to three requirements: (1) Procedures for military courts must conform to district-court rules insofar as the President "considers practicable"; (2) the procedures 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 requirement, 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.

As the Court further instructs, even assuming the first and second requirements of §836 are satisfied here--a matter of some dispute--the third requires us to compare the military-commission procedures with those for courts-martial and determine, to the extent there are deviations, whether greater uniformity would be practicable. Although we can assume the President's practicability judgments are entitled to some deference, the Court observes that Congress' choice of language…is best understood to allow the selection of procedures based on logistical constraints, the accommodation of witnesses, the security of the proceedings, 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….

The Court is correct to concentrate on one provision of the law of war that is applicable to our Nation's armed conflict with al Qaeda in Afghanistan and, as a result, to the use of a military commission to try Hamdan. That provision is Common Article 3 of the four Geneva Conventions of 1949. It prohibits, as relevant here, "[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." The provision is part of a treaty the United States has ratified and thus accepted as binding law. By Act of Congress, moreover, violations of Common Article 3 are considered "war crimes," punishable as federal offenses, when committed by or against United States nationals and military personnel. There should be no doubt, then, that Common Article 3 is part of the law of war as that term is used in §821….

Assuming the President has authority to establish a special 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," The terms of this general standard are yet to be elaborated and further defined, but Congress has required 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….

The regular military courts in our system are the courts-martial established by congressional statutes. Acts of Congress confer on those courts the jurisdiction to try "any person" subject to war crimes prosecution. As the Court explains, moreover, while special military commissions 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….

In addition, whether or not the possibility, contemplated by the regulations here, of midtrial procedural changes could by itself render a military commission impermissibly irregular, 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. 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 constitutional limitations, see Ex parte Milligan, 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 military 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 authorization--can be "regularly constituted" by the standards of our military justice system only if some practical need explains deviations from court-martial practice. Relevant concerns, as noted earlier, relate to logistical constraints, accommodation of witnesses, security 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 congressional statutes can be controlling, including the congressional 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. Captured 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 Osama bin Laden's bodyguards, providing security services to bin Laden, and receiving weapons training at a terrorist camp. Nevertheless, the circumstances 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. The following analysis, which expands on the Court's discussion, explains my reasons for reaching this conclusion.

To begin with, the structure and composition of the military commission deviate from conventional court-martial standards. Although these deviations raise questions about the fairness of the trial, no evident practical need explains them….

As compared to the role of the convening authority in a court-martial, the greater powers of the Appointing Authority here--including even the resolution of dispositive issues in the middle of the trial--raise concerns that the commission's decisionmaking may not be neutral. If the differences are supported by some practical need beyond the goal of constant and ongoing supervision, that need is neither apparent from the record nor established by the Government's submissions….

These structural differences between the military commissions and courts-martial--the concentration of functions, including 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 institutions created and regulated by Congress--remove safeguards 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' requirement 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. As the Court explains, the Military Commission Order abandons the detailed Military Rules of Evidence, which are modeled on the Federal Rules of Evidence in conformity with §836(a)'s requirement of presumptive compliance with district-court rules.

Instead, the order imposes just one evidentiary rule: "Evidence shall be admitted if ... the evidence would have probative value to a reasonable person," Although it is true some military commissions applied an amorphous evidence standard in the past, the evidentiary rules for those commissions were adopted before Congress enacted the uniformity requirement as part of the UCMJ. 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, and use of classified information. Indeed, the deposition-testimony provision specifically mentions military commissions and thus is one of the provisions the Government concedes must be followed by the commission at issue. That provision authorizes admission of deposition testimony only if the witness is absent for specified reasons--a requirement that makes no sense if military commissions may consider all probative evidence….

The rule here could permit admission of multiple hearsay and other forms of evidence generally prohibited on grounds of unreliability. Indeed, the commission regulations specifically contemplate admission of unsworn written statements, and they make no provision for exclusion of coerced declarations save those "established to have been made as a result of torture," Besides, even if 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 presiding officer's evidence rulings and determine themselves, by majority vote, whether to admit the evidence.

As the Court explains, the Government has made no demonstration of practical need for these special rules and procedures, either in this particular case or as to the military commissions in general, nor is any such need self-evident. For all the Government's regulations and submissions 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 commission exceeds the bounds Congress has placed on the President's authority in the UCMJ. 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 Congress has provided. By those standards the military commission 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 judicial guarantees which are recognized as indispensable by civilized peoples,"--necessarily requires that the accused have the right to be present at all stages of a criminal trial….

I likewise see no need to address the validity of the conspiracy charge against Hamdan--an issue addressed at length in Part V of Justice Stevens' opinion…

Finally, for the same reason, I express no view on the merits of other limitations on military commissions described as elements of the common law of war in Part V of Justice Stevens' opinion.

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 Justice 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 jurisdiction 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 natural 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 exercise of sound equitable discretion, not be exercised.

The D[etainee] T[reatment] A[ct] 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….

An ancient and unbroken line of authority attests that statutes ousting jurisdiction unambiguously apply to cases pending at their effective date….

"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….

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 petitioner's claims. The Court having concluded 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 Court's evident belief that it is qualified to pass on the "[m]ilitary necessity," of the Commander in Chief's decision to employ a particular form of force against our enemies is so antithetical to our constitutional structure that it simply cannot go unanswered. I respectfully dissent.

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 Congress. Accordingly, it is important to take measure of the respective roles the Constitution assigns to the three branches of our Government in the conduct of war.

As I explained in Hamdi v. Rumsfeld, the structural advantages attendant to the Executive Branch--namely, the decisiveness, " 'activity, secrecy, and dispatch' " that flow from the Executive's " 'unity,' " led the Founders to conclude 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." Consistent with this conclusion, the Constitution vests in the President "[t]he executive Power," Art. II, §1, provides that he "shall be Commander in Chief" of the Armed Forces, and places in him the power to recognize foreign governments. This Court has observed that these provisions confer upon the President broad constitutional authority to protect the Nation's security in the manner he deems fit. Prize Cases.

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." Rather, in these domains, 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 particular powers not specifically enumerated.

When "the President acts pursuant to an express or implied authorization from Congress," his actions are " 'supported 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.' Youngstown Sheet & Tube Co. v. Sawyer. Accordingly, in the very context that we address today, this Court has concluded that "the detention and trial of petitioners--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."

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 President "to use 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 ... 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). As a plurality of the Court observed in Hamdi, the "capture, detention, and trial of unlawful combatants, by 'universal agreement and practice,' are 'important incident[s] of war,'" and are therefore "an exercise of the 'necessary and appropriate force' Congress has authorized the President to use." Hamdi's observation that military commissions are included within the AUMF's authorization is supported by this Court's previous recognition 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, Quirin.

Although the Court concedes the legitimacy of the President's use of military commissions in certain circumstances, it suggests that the AUMF has no bearing on the scope of the President's power to utilize military commissions in the present conflict. …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 authorization of "the initiation of war" with its attendant authorization of "the employment of all necessary and proper agencies for its due prosecution. 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.

I note the Court's error respecting the AUMF not because it is necessary to my resolution of this case--Hamdan's military 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 previously noted, our duty to defer to the Executive's military and foreign policy judgment is at its zenith; it does not countenance the kind of second-guessing the Court repeatedly engages in today.

It is within this framework that the lawfulness of Hamdan's commission should be examined.

…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," and that he "conspired and agreed with [al Qaeda] to commit ... offenses triable by military commission,"

The common law of war establishes that Hamdan's willful and knowing membership in al Qaeda is a war crime chargeable 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." 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 involved in the attacks on the U. S. Embassies in Kenya and Tazania in August 1998, the attack on the USS COLE in October 2000, and the attacks on the United States on September 11, 2001." These allegations, 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 unauthorized 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 war." 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." This conclusion is unsurprising, as it is a "cardinal principle of the law of war ... that the civilian population must enjoy complete immunity"…Accordingly, on this basis alone, "the allegations of [Hamdan's] charge, tested by any reasonable standard, adequately allege a violation of the law of war." Yamashita.

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 military tribunals convened by the United States at Nuremberg….

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. These allegations further confirm that Hamdan is triable before a law-of-war military commission for his involvement with al Qaeda….

Separate and apart from the offense of joining a contingent of "uncivilized combatants who [are] not ... likely to respect the laws of war," Hamdan has been charged with "conspir[ing] and agree[ing] with ... the al Qaida organization ... to commit ... offenses triable by military commission," Those offenses include "attacking civilians; attacking civilian objects; murder by an unprivileged belligerent; and terrorism." This, too, alleges a violation of the law of war triable by military commission….

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 authority, 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." This judgment starkly confirms that the plurality has appointed itself the ultimate arbiter of what is quintessentially a policy and military judgment, namely, the appropriate military measures to take against those who "aided the terrorist attacks that occurred on September 11, 2001." The plurality's suggestion that Hamdan's commission is illegitimate because it is not dispensing swift justice on the battlefield is unsupportable. Even a cursory review 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 circumstances alike. Traditionally, 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 precisely 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 organization 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 captured American soldiers. But according to the plurality, when our Armed Forces capture those who are plotting terrorist 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," in the midst of the attack itself, in order to bring them to justice. Not only is this conclusion fundamentally inconsistent with the cardinal principal of the law of war, namely protecting non-combatants, but it would sorely hamper the President's ability to confront and defeat a new and deadly enemy….

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. This position is untenable.

…The Court provides no explanation why the President's determination that employing court-martial procedures in the military commissions established pursuant to Military Commission 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 precisely 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 intrusion or inquiry.' And, in the context of the present conflict, it is exactly the kind of determination Congress countenanced when it authorized the President to use all necessary and appropriate force against our enemies. Accordingly, the President's determination is sufficient to satisfy any practicability requirement imposed by Article 36(b)….

The Court contends that Hamdan's military commission is also unlawful because it violates Common Article 3 of the Geneva Conventions. Furthermore, Hamdan contends that his commission is unlawful because it violates various provisions of the Third Geneva Convention. These contentions are untenable.

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." "Pursuant to [his] authority as Commander in Chief and Chief Executive of the United States," the President has "accept[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 relevant conflicts are international in scope and common Article 3 applies only to 'armed conflict not of an international character.' " 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." Our duty to defer to the 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 conflict

The President's interpretation of Common Article 3 is reasonable and should be sustained…Instead, the Court, without acknowledging its duty to defer to the President, adopts its own, admittedly plausible, reading of Common Article 3. But where, as here, an ambiguous treaty provision ("not of an international character") is susceptible of two plausible, and reasonable, interpretations, our precedents require us to defer to the Executive's interpretation.

But even if Common Article 3 were judicially enforceable and applicable to the present conflict, petitioner would not be entitled to relief….

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 because it "deviate[s] from [the procedures] governing courts-martial." But there is neither a statutory nor historical requirement that military commissions conform to the structure and practice of courts-martial. A military 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 constituted court[s]."

Similarly, the procedures to be employed by Hamdan's commission afford "all the judicial guarantees which are recognized as indispensable by civilized peoples." Neither the Court nor petitioner disputes the Government's description of those procedures….

Notwithstanding these provisions, which in my judgment easily satisfy the nebulous standards of Common Article 3, the plurality concludes that Hamdan's commission is unlawful because of the possibility that Hamdan will be barred from proceedings and denied access to evidence that may be used to convict him. But, under the commissions' rules, the Government may not impose such bar or denial on Hamdan if it would render his trial unfair, 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) intelligence, including the sources and methods for gathering such intelligence. The Government has explained 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." 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 unarguable' that no governmental interest is more compelling than the security of the Nation," 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 operates--identifying where its operatives are, how it plans attacks, who directs operations, and how they communicate." We should not rule out the possibility 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 unlawful 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 installations so long as it did not deprive the accused of a fair trial. Accordingly, the President's understanding of the requirements of Common Article 3 is entitled to "great weight"….

For these reasons, I would affirm the judgment of the Court of Appeals.

Justice Alito, with whom Justices Scalia and 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.

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 prohibits petitioner's trial because the commission before which he would be tried is not "a regularly constituted court," Third Geneva Convention. I disagree with this holding because petitioner's commission is "a regularly constituted court."

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 shallbe bound to apply, as a minimum, the followingprovisions:

... [T]he following acts are and shall remain prohibited ... :

"(1) [T]he passing of sentences and the carrying out of executions without previous judgment pronounced by "(d) a regularly constituted court affording all the judicial guarantees which are recognized as indispensable by civilized peoples."

Common Article 3 thus imposes three requirements. Sentences may be imposed only by (1) a "court" (2) that is "regularly constituted" and (3) that affords "all the judicial guarantees which are recognized as indispensable by civilized peoples."

…The second element ("regularly constituted") is the one on which the Court relies, and I interpret this element to require that the court be appointed or established in accordance with the appointing country's domestic law. I agree with the Court, that, as used in Common Article 3, the term "regularly" is synonymous with "properly." The term "constitute" means "appoint," "set up," or "establish," 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

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 countries with different government structures handle this matter 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.

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 constituted court" (a) because "no evident practical need explains" why its "structure and composition ... deviate from conventional court-martial standards," and (b) because, contrary to 10 U. S. C. §836(b), the procedures specified for use in the proceeding before the military commission impermissibly differ from those provided under the Uniform Code of Military Justice (UCMJ) for use by courts-martial, I do not believe that either of these grounds is sound.

I see no basis for the Court's holding that a military commission cannot be regarded as "a regularly constituted court" unless it is similar in structure and composition to a 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 military court must be viewed as having been improperly constituted. Tribunals that vary significantly in structure, composition, and procedures may all be "regularly" or "properly" 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 before 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….If Common Article 3 had been meant to incorporate a "uniformity principle," it presumably 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 commission at issue here is not a "regularly constituted court" because its structure and composition differ from those of a court-martial….

I also disagree with the Court's conclusion that petitioner's military commission is "illegal," because its procedures 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 contemplated by the UCMJ, and even if it is assumed for the sake of argument 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 constituted" 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 follow 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 commission proceedings are improper, the appropriate remedy is to proscribe the use of those particular procedures, not to outlaw 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 universally recognized fundamental rights--I conclude that all of these elements are satisfied in this case.

…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 deeming the commissions to be illegitimate. The Court questions the following two procedural rules: the rule allowing the Secretary of Defense to change the governing rules " 'from time to time' " (which does not rule out mid-trial changes), 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), 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 ongoing 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 commission proceedings, the Court does not suggest that this rule violates the international standard incorporated into Common Article 3 ("the judicial guarantees which are recognized as indispensable by civilized peoples,"). Rules of evidence differ from country to country, and much of the world does not follow aspects of our evidence rules, such as the general prohibition against the admission of hearsay. If a particular accused claims to have been unfairly 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 commission 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….

For these reasons, I respectfully dissent.