542 U.S. 507 (2004)
The citizen-detainee was born in the United States, detained in Afghanistan during the United States' military action against the Taliban regime, and transferred to the United States. Pursuant to a government official's declaration, the Government contended that the citizen-detainee was an enemy combatant. Aside from unspecified screening processes and military interrogations, the citizen-detainee received no due process.
- The Court determined that the Authorization for Use of Military Force (AUMF), 115 Stat. 224, authorized the detention of individuals in the citizen-detainee's circumstances and that the AUMF satisfied 18 U.S.C.S. § 4001(a)'s requirement that a detention be "pursuant to an Act of Congress."
- However, under the Mathews analysis, the Court determined that the citizen-detainee, seeking to challenge his classification as an enemy combatant, was entitled to receive notice of the factual basis for his classification, and a fair opportunity to rebut the Government's factual assertions before a neutral decisionmaker.
- The Court rejected the Government's assertion that separation of powers principles mandated a heavily circumscribed role for the courts in such circumstances.
The Supreme Court vacated the appellate court's judgment and remanded the case for further proceedings.