This Note argues that courts should apply the clear statement principle whenever the AUMF—or the NDAA 2012—is invoked to detain individuals arrested in the United States in indefinite military detention without trial, so long as their status as an enemy combatant is in dispute. The clear statement principle serves the purpose of the constitutional avoidance canon. It rests on the principle that “[i]n traditionally sensitive areas . . . the requirement of clear statement assures that the legislature has in fact faced, and intended to bring into issue, the critical matters involved in the judicial decision.” Reading § 1021 of the NDAA 2012 and the AUMF broadly would raise serious due process and separation of powers concerns. It would amount to displacing civilian law enforcement with martial law on U.S. territory, thereby circumventing the individual rights and the restraints on government provided for in the Constitution. Supreme Court precedent in cases involving ambiguous wartime statutes raising similar concerns supports the application of a clear statement principle in this context.
Several scholars of constitutional law have advanced arguments about when and how a clear statement principle should apply to the AUMF on U.S. territory. These arguments have generally focused on the status of the individual as the triggering factor. Some have argued that the clear statement requirement is triggered where the AUMF is invoked to detain U.S. citizens on U.S. territory, but that it does not apply to noncitizens. Others have argued that it applies if civilians are detained on U.S. territory, but not if the individual is deemed by the executive branch to be a “combatant.” This Note argues that these arguments fail to adequately address the constitutional concerns raised by a broad construction of the AUMF detention authority as applied on U.S. territory. First, theories that make citizenship the trigger for the clear statement principle ignore that, as a matter of settled constitutional law, the rights guaranteed under the Due Process Clause apply to citizens and noncitizens alike. Reading the AUMF as authorizing indefinite military detention without trial of noncitizens arrested on U.S. territory would violate the Due Process Clause of the Fifth Amendment. Second, arguments that exclude those deemed to be “enemy combatants”—at least where that status is in dispute—render the clear statement principle meaningless in practical effect. It would never be triggered because the executive branch is always going to claim that the individual it wishes to detain under the AUMF is an “enemy combatant” under its definition of that term. This approach thus leaves courts in the same position as they would be without the clear statement principle: they are forced to judge the legitimacy of the executive branch’s exercise of military power in a particular case by interpreting ambiguous statutory language as applied to a particular set of factual circumstances. This argument also fails to give adequate attention to the more fundamental question of whether it is constitutionally legitimate to apply law-of-war principles in the United States, in the absence of battlefield conditions, in lieu of the criminal justice system.