In habeas proceedings brought by aliens detained at Guantanamo after being captured in Afghanistan or elsewhere abroad and designated enemy combatants by tribunals, the Court rules that petitioners have the constitutional privilege of habeas corpus. The procedures for review of the detainees' status provided by the Detainee Treatment Act of 2005 are not an adequate and effective substitute for habeas corpus, and consequently, section 7 of the Military Commissions Act of 2006 (MCA), operates as an unconstitutional suspension of the writ.