Common Article 3 is denominated "common" because it appears in each of the four Geneva Conventions. It sets forth the basic human rights that apply to all persons detained in conflicts "not of an international character." The administration has long argued that because the struggle with al-Qaeda is international, not domestic, Common Article 3 does not apply. The Court rejected that view, explaining that the phrase "not of an international character" was meant in its literal sense, to cover all conflicts not between nations, or "inter-national" in character. (Conflicts between nations are covered by other provisions of the Geneva Conventions.) Since the war with al-Qaeda is a conflict between a nation and a nonstate force, the Court ruled, it is "not of an international character," and Common Article 3 applies.

The Bush administration devoted much of its brief to arguing that the Geneva Conventions are not enforceable by individuals in U.S. courts, and Hamdan's lawyers devoted equal space to arguing the opposite. The Court, however, neatly sidestepped that question, finding that it need not decide it because Congress had incorporated the Geneva Conventions into U.S. law when it required that military tribunals adhere to the "law of war."

The fact that the Court decided the case at all in the face of Congress's efforts to strip the Court of jurisdiction is remarkable in itself. That the Court then broke away from its history of judicial deference to security claims in wartime to rule against the President, not even pausing at the argument that the decisions of the commander in chief are "binding on the courts," suggests just how troubled the Court's majority was by the President's assertion of unilateral executive power. That the Court relied so centrally on international law in its reasoning, however, is what makes the decision truly momentous.

3.

The Hamdan decision has sweeping implications for many aspects of the Bush doctrine, including military tribunals, NSA spying, and the interrogation of al-Qaeda suspects. With respect to trying alleged war criminals, the administration now has two options. Without changing the law, it can put into effect the regular court-martial procedures that are used for trying members of the American military. The administration has already rejected that option, and has instead said that it will ask Congress for explicit approval of military tribunals that afford defendants fewer protections than courts-martial would. Because the Court's decision rests on statutory grounds, the President could in theory seek legislation authorizing the very procedures that the Court found wanting. Already, Senators Jon Kyl, Lindsay Graham, Arlen Specter, and others have announced that they will seek legislation to authorize military tribunals.

But because the Court also ruled that Common Article 3 of the Geneva Conventions applies, and that the tribunals as currently constituted violate that provision, legislative reform is not so simple. Were Congress to approve the tribunals in their present form, it would thereby be authorizing a violation of Common Article 3. Congress unquestionably has the legal power, as a matter of domestic law, to authorize such a violation. Treaties and legislation are said to be of the same stature, and therefore Congress may override treaties by enacting superseding laws. But passing a law that blatantly violates a treaty obligation is no small matter. And the U.S. has a strong interest in respecting the Geneva Conventions, since they protect our own soldiers when captured abroad. It is one thing to put forward an arguable interpretation of the treaty, as the administration did in contending that Common Article 3 simply did not apply in Hamdan's case. It is another thing to blatantly violate the treaty. As a result, the Hamdan decision is likely to force the administration to make whatever procedures it adopts conform to the dictates of Common Article 3.

The Court's decision also has significant implications for the controversy over President Bush's authorization of NSA spying without court approval. On its face, that program violates the Foreign Intelligence Surveillance Act of 1978, which requires that a special court grant permission for wiretapping. The administration has defended the NSA program with two arguments. It claims that Congress implicitly authorized the program when it enacted the Authorization for Use of Military Force (AUMF) against al-Qaeda in 2001. And it maintains that the President has inherent unilateral power to authorize such surveillance as commander in chief, notwithstanding the fact that it was criminally banned by the Foreign Intelligence Surveillance Act.

In Hamdan's case, the administration similarly argued that the AUMF of 2001 authorized the military tribunals, and that in any event the President had unilateral authority to create the tribunals as commander in chief. The Court dismissed both contentions. It reasoned that since the AUMF said nothing specifically about military trials, it could not override the explicit congressional legislation restricting the use of military tribunals. And it ruled that whatever inherent power the President might have in the absence of congressional legislation, "he may not disregard limitations that Congress has, in proper exercise of its own war powers, placed on his powers.

These conclusions squarely refute the only arguments the President has advanced to justify the NSA spying program. The AUMF of 2001 is as silent on wiretapping as it is on military tribunals. Here too, then, the President may not disregard Congress's express limitations on his powers.

4.

The most far-reaching implications of the Court's decision, however, concern the interrogation of al-Qaeda suspects. The administration has since the outset of the conflict sought to evade the limitations set by international law on coercive interrogation, reasoning that the need for "actionable intelligence" trumps the human dignity of its detainees. According to a January 25, 2002, memo from then White House Counsel Alberto Gonzales to the President, the desire to extract information from suspects was a prime motivating factor behind the administration's decision that the Geneva Conventions do not apply to the conflict with al-Qaeda. The Justice Department's infamous "torture memo" of August 2002 argued, among other things, that threatening death and inflicting pain short of death or organ failure were not "torture," and that in any event the President as commander in chief could order torture despite a criminal statute prohibiting it.

The administration also secretly interpreted the International Convention Against Torture and Other Cruel, Inhuman and Degrading Treatment, ratified by Congress in 1994, to permit cruel and degrading treatment of foreign nationals held outside U.S. borders. When Senator John McCain convinced Congress to overrule that interpretation by statute, the administration lobbied members of Congress to ensure that the McCain Amendment contained no enforceable sanctions. It then attached a "signing statement" to the law proclaiming that the President would obey the amendment only to the extent that it did not interfere with his decisions as commander in chief --in other words, only when he chose to obey it.

The Hamdan decision, while not explicitly addressed to the question of interrogation, should resolve this debate. Common Article 3 of the Geneva Conventions, which the Court has now authoritatively declared applies to the conflict with al-Qaeda, requires that all detainees be "treated humanely," and protects them against "outrages upon personal dignity, in particular humiliating and degrading treatment." Moreover, the federal War Crimes Act makes it a felony, punishable in some instances by death, to violate Common Article 3 in any way. Thus, CIA and military interrogators are now on notice that any inhumane treatment of a detainee subjects them to prosecution as a war criminal. While they might be confident that the Bush administration would not prosecute them, they cannot be sure that a future administration would overlook such war crimes. And it is quite possible that government officials might actually decide not to commit war crimes -- now that they know they are war crimes -- even if prosecution is unlikely.