In Congressional Authorization and the War on Terrorism, (1) we presented a framework for interpreting Congress's September 18, 2001 Authorization for Use of Military Force (2) (AUMF), the central statutory enactment related to the war on terrorism. Congressional Authorization addressed a puzzling gap in the academic literature: although both constitutional theory and constitutional practice suggest that the validity of presidential wartime actions depends to a significant degree on their relationship to congressional authorization, the meaning and implications of the AUMF have received little attention in the academic debates over the war on terrorism.
The framework in Congressional Authorization built on the plurality opinion in Hamdi v. Rumsfeld, (3) which devoted significant attention to the AUMF. The framework, in a nutshell, is as follows: The meaning of the AUMF should be determined in the first instance by its text, as informed by a comparison with authorizations of force in prior wars, including declared wars. In clarifying the meaning of the "necessary and appropriate force" that Congress authorized, (4) courts should look primarily to two interpretive factors: Executive Branch practice during prior wars and the international laws of war. Delegation concerns should not play a significant role in interpreting the AUMF, but a clear statement requirement is appropriate when the President takes actions under the AUMF that restrict the liberty of non-combatants in the United States.
Congressional Authorization did not attempt to resolve every question that might arise under the AUMF. Instead, it sought to establish a starting point for analysis that would be useful to courts and the Executive Branch in addressing the complex and sometimes novel issues in the war on terrorism, and to stimulate academic discussion of Congress's important enactment. The latter goal is well served by the three Replies to Congressional Authorization in this issue of the Harvard Law Review.
Although each of the Replies approaches the AUMF from a different perspective, none expresses fundamental disagreement with our framework. Professors Goodman and Jinks describe our framework as "useful," but maintain that we have understated the importance of the international laws of war within the framework. (5) Professor Sunstein argues that administrative law should play a greater role than we suggested, and the international laws of war a less substantial role. He also advocates a broader clear statement requirement. (6) Otherwise, he approaches the AUMF in ways similar to Congressional Authorization, and reaches similar conclusions. Professor Tushnet suggests that ours is a reasonable approach to interpreting the AUMF, but he maintains that its very reasonableness demonstrates the danger of relying on Congress to police executive power during wartime, and suggests that the only solution may be a constitutional amendment. (7)
Below, we address three issues raised by these Replies: first, the proper role of the international laws of war in the interpretation of the AUMF; second, the circumstances in which a clear statement requirement is appropriate in ascertaining the scope of the AUMF; and third, the implications of our analysis for the ability of the current constitutional system to ensure optimal tradeoffs between liberty and security during war.
I. THE AUMF AND THE INTERNATIONAL LAWS OF WAR
Congressional Authorization argued that, in broadly authorizing the President to use "all necessary and appropriate force," Congress implicitly authorized actions permitted under the international laws of war. It also argued that, because the laws of war can inform the scope of Congress's authorization, they can also inform limitations on that authorization. Absent textual or other evidence to the contrary, therefore, the AUMF should not be viewed as authorizing presidential actions in violation of the laws of war. …