Background

1. Military commissions are legitimate forums to try enemy combatants because they've been approved by Congress.
2. The Geneva Convention is a treaty between nations and as such it doesn't confer individual rights and remedies.
3. Even if the Geneva Convention could be enforced in U.S. courts, it wouldn't be of assistance to Hamdan at the time because, for a conflict such as the war against al-Qaeda that isn't between two countries, it guarantees only a certain standard of judicial procedure—a "competent tribunal"—without speaking to the jurisdiction in which the prisoner must be tried.
4. Under the terms of the Geneva Convention, al Qaeda and its members are not covered.
5. Congress authorized such activity by statute.
6. The judicial branch of the United States government can't enforce the Convention, thus invalidating Hamdan's argument that he can't be tried until after his prisoner of war status is determined. The petition was filed on behalf of Hamdan by Neal Katyal of Georgetown University Law Center and Seattle University School of Law alumnus Lt. Commander Charles Swift of the U.S. Navy. Seattle law firm Perkins Coie provided the additional legal counsel for Hamdan.
      The case was argued before the court on 28 March 2006. Katyal argued on behalf of Hamdan, and Paul Clement, the Solicitor General of the United States, argued on behalf of the government. Chief Justice Roberts recused himself because he'd previously ruled on this case as part of the three judge panel on the United States Court of Appeals for the District of Columbia Circuit. Critics called for Justice Antonin Scalia to recuse himself, since he'd made allegedly improper comments about the decision of the case prior to hearing oral arguments ("I'm not about to give this man who was captured in a war a full jury trial. I mean it's crazy") but he chose not to do so.
      The Supreme Court announced its decision on 29 June 2006. The Court reversed the ruling of the Court of Appeals, holding that President Bush didn't have authority to set up the war crimes tribunals and finding the special military commissions illegal under both military justice law and the Geneva Convention.

   Stevens' opinion for the Court

   Associate Justice John Paul Stevens wrote the opinion for the Court, which commanded a majority only in part.
      The Stevens opinion began with the issue of jurisdiction, denying the U.S. government's motion to dismiss under Section 1005 of the Detainee Treatment Act of 2005 (DTA), which gave the D.C. Circuit Court of Appeals "exclusive" jurisdiction to review decisions of cases being tried before military commissions. Congress didn't include language in the DTA that might have precluded Supreme Court jurisdiction, making the government's argument to the Court unpersuasive. The government's argument that Schlesinger v. Councilman, 420 U.S. 738 (1975), precludes Supreme Court review was similarly rejected. Councilman applied to a member of the U.S. military who was being tried before a military "court-martial." In contrast, Hamdan isn't a member of the U.S. military, and would be tried before a military "commission," not a court-martial. To the court, the more persuasive precedent was Ex parte Quirin, in which the court recognized its duty to enforce relevant Constitutional protections by convening a special Term and expediting review of a trial by military convention. The opinion explicitly stated that, because DTA didn't bar it from considering the petition, it was unnecessary to decide whether laws unconditionally barring habeas corpus petitions would unconstitutionally violate the Suspension Clause.
      The opinion next addressed the substantive issues of the case. It explicitly didn't decide whether the President possessed the Constitutional power to convene military commissions like the one created to try Hamdan. Even if he possessed such power, those tribunals would either have to be sanctioned by the "laws of war," as codified by Congress in Article 21 of the Uniform Code of Military Justice (UCMJ), or authorized by statute. As to the statutory authorization, there's nothing in the Authorization for Use of Military Force (AUMF) "even hinting" at expanding the President's war powers beyond those enumerated in Art. 21. Instead, the AUMF, the UCMJ, and the DTA "at most acknowledge" the President's authority to convene military commissions only where justified by the exigencies of war, but still operating within the laws of war.
      As to the laws of war, to the majority these necessarily include the UCMJ and the Geneva Conventions, each of which require more protections than the military commission provides. The UCMJ, Art. 36 (b), which requires that rules applied in courts-martial and military commissions be "uniform insofar as practicable." Stevens found several substantial deviations, including:
   
7. The defendant and the defendant's attorney may be forbidden to view certain evidence used against the defendant; the defendant's attorney may be forbidden to discuss certain evidence with the defendant;
8. Evidence judged to have any probative value may be admitted, including hearsay, unsworn live testimony, and statements gathered through torture; and
9. Appeals are not heard by courts, but only within the Executive Branch (with an exception not here relevant).

The majority opinion notes that language in the Congressional Record that the Scalia dissent cites was inserted into the Record after the legislation had been enacted, by Senators Lindsey Graham (R-SC) and Jon Kyl (R-AZ), and includes falsified quotations attributed to other persons. (The Department of Justice brief also relied on the made-up colloquy).

Breyer's concurrence

Justice Breyer wrote a one-page concurring opinion, joined by Justices Kennedy, Souter, and Ginsburg. Breyer contended that the commissions are not necessarily categorically prohibited, as long as Congress approves them: » ...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 doesn't 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.

Kennedy's concurrence

Justice Kennedy wrote an opinion concurring in part, joined as to parts I and II by Justices Souter, Ginsburg, and Breyer.
   In Part One of Kennedy's concurrence, he raises his concern for the separation of powers; specifically, how one branch can control all the elements of a case, including avenues of review and appeal.
   Part Two describes the differences between the procedures of the military commissions and the procedures prescribed by the UCMJ (fewer jury members, different rules of evidence, et al.). These differences demonstrate that the commissions don't operate under the rules of military courts-martial, and raise issues of neutrality with respect to the military judges involved. The negation of fairness safeguards renders the commission a judicial entity which isn't a "regularly constituted court", as required in the Geneva Convention. In sum, Kennedy writes that the commission exceeds congressional bounds, though the Congress is free to re-write the law as they see fit.
   The third and final Part lists some of Kennedy's reservations. He wouldn't say that the defendant must be present at all stages of the trial. There should be a reluctance to consider the applicability of Article 75 of Protocol I, since America never signed it and thus it isn't binding. Kennedy writes that he feels it wasn't necessary to delve into the validity of the conspiracy charge, and he expresses no view on the merits of the other limitations of the commission noted in Part V of the Decision.

Scalia's dissent

Justice Scalia wrote a dissenting opinion that focuses primarily on issues of jurisdiction, and was joined by Justices Thomas and Alito.
   Scalia calls the Court's conclusion to hear the case "patently erroneous." His first argument relies on the part of the Detainee Treatment Act (DTA) (effective December 30, 2005) that states "[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. Scalia's opinion is that this clause suffices to deny the Supreme Court jurisdiction over the case, calling the majority's reading of the effectiveness provisions of §1005(h), a "mess". He cites Bruner v. United States and other cases granting "immediate effect in pending cases, absent an explicit statutory reservation." He criticizes the majority's use of Senate floor debate records to bolster their interpretation, writing that it "makes no difference" that the language in support of his position was inserted after the law was voted upon. He also accuses the majority of ignoring the President's Signing Statement.
   Furthermore, he anticipates that expanding the jurisdictions able to hear writs of habeas corpus from Guantanamo Bay would create excessive load on the court system.
   In addition, Scalia states that the original military tribunal wasn't shown to be inadequate. Regarding the application of the Suspension Clause of the Constitution, Scalia points to Johnson v. Eisentrager.
   In its second major argument, Scalia's opinion argues that petitioners such as Hamdan held outside the territorial jurisdiction of the United States lack the right to the writ of habeas corpus. He points in a footnote to Hamdi v. Rumsfeld, under which he claims Hamdan "is already subject to indefinite detention" "after an adverse determination by his CSRT."
   Finally, Justice Scalia chastises the Court for taking equity jurisdiction of the case and draws an analogy with Schlesinger v. Councilman, 420 U.S. 738 (1975). In that case, the Supreme Court declined passing judgment on the decision of a military court-martial before it finished its work; Scalia argues that likewise, the military commissions in Cuba have not yet ended their work regarding Hamdan and therefore shouldn't be subject to judicial oversight.
   Citing his dissent in Hamdi v. Rumsfeld, Thomas briefly reprised the roles granted by the Constitution to the three different branches in time of war. He argued that under the framework established in Ex parte Quirin and Youngstown Sheet & Tube Co. v. Sawyer, President Bush's decision to try Hamdan before a military commission "is entitled to a heavy measure of deference," inasmuch as Congress had authorized the President to use all necessary and appropriate force to prevent future acts of terrorism when it passed the Authorization for Use of Military Force.
   Thomas disagreed strongly with the plurality’s determination that the legality of the charges against Hamdan are doubtful because he was charged "not with an overt act for which he was caught redhanded...but with an 'agreement' the inception of which long predated...the [relevantarmed conflict]." He lambasted the plurality for second-guessing the Executive’s judgment, arguing that the Court’s disagreement was based upon "little more than its unsupported assertions" and constituted "an unprecedented departure from the traditionally limited role of the courts with respect to war and an unwarranted intrusion on executive authority." Thomas further disagreed with the plurality’s assumption that the date of the enactment of the AUMF constituted the start of war, suggesting that Osama bin Laden's declaration of jihad in August 1996 could be considered a declaration of war. Under this view, the enactment by Congress of the AUMF didn't mark the beginning of the conflict with al Qaeda, but rather authorized the Executive to use force to combat it. Additionally, Thomas wrote that under the common law of war, which is "flexible and evolutionary in nature," war courts are permitted a degree of latitude in their jurisdiction. In holding otherwise, the plurality failed to properly defer to the judgment of the Executive and military commanders.
   Referring to the Court’s recent decision in Rapanos v. United States, Thomas noted with some incredulity that while the Justices that in the instant decision "disregard[ed] the commander-in-chief’s wartime decisions," they'd no trouble deferring to the judgment of the Corps of Engineers in upholding the agency’s "wildly implausible conclusion that a storm drain is a tributary of the waters of the United States." "It goes without saying," Thomas added, "that there's much more at stake here than storm drains."
   Thomas likewise disagreed with the plurality’s holding that even if the government had charged Hamdan with a crime that was clearly cognizable by military commission, the commission would still lack power to proceed because it doesn't comply with the terms of the UCMJ and the four Geneva Conventions signed in 1949. He again emphasized that the jurisdiction of military commissions isn't prescribed by statute but is rather "adapted in each instance to the need that called it forth." Thomas argued that the Court’s conclusion that Article 36 of the UCMJ amounts to an attempt by Congress to curb the Executive’s power is "contrary to the text and structure of the UCMJ" and also inconsistent with prior decisions of the Court. Addressing Hamdan’s claims under the Geneva Convention, Thomas argued that these are foreclosed by the Court’s holding in Johnson v. Eisentrager, where the majority noted that the respondents couldn't assert "that anything in the Geneva Convention makes them immune from prosecution or punishment for war crimes." Further, even if Hamdan’s claim under Common Article 3 wasn't foreclosed by Eisentrager, it's nevertheless meritless insofar as the President has accepted the determination of the Department of Justice that Common Article 3 of Geneva doesn't extend to al Qaeda detainees. Thomas asserted that the Court’s duty in this instance to "defer to the President’s understanding of the provision at issue" is made even more acute by the fact that he's acting pursuant to his authority as Commander-in-Chief.

Alito's dissent

In a seven page dissent, Alito sided with Thomas and Scalia's explanation of why they believe the courts had no jurisdiction for this case. He explained why he believed the military commission in this case was legal. Alito disagreed with the holding of the Court which found that military commissions didn't meet the definition of a "a regularly constituted court" as required in Common Article 3 of the Geneva Conventions. Alito argued that Common Article 3 was satisfied in Hamdan because the military commissions: