Supporters of the camp say it is necessary to facilitate intelligence gathering and that without military commissions many "enemy combatants" could not be prosecuted. Evidence against some of them was obtained through sensitive intelligence operations and using methods that likely violate constitutional protections, legal analysts say.
The Supreme Court ruling does not address whether Guantanámo should remain open or shut down. Instead, it focuses on the process for holding commission trials established by the president in the aftermath of the 9/11 terror attacks.
Lawyers working on Hamdan's behalf had charged that President Bush violated US and international law in ordering specially formulated commission trials at Guantánamo.
The Supreme Court agreed.
"It bears emphasizing that Hamdan does not challenge, and we do not today address, the government's power to detain him for the duration of active hostilities," Stevens writes. "But in undertaking to try Hamdan and subject him to criminal punishment, the executive is bound to comply with the rule of law that prevails in this jurisdiction."
The case was being closely watched because it required the justices to confront the fundamental constitutional tension between presidential, congressional, and judicial power during times of national peril.
In reaching their decision, the majority justices said provisions within the Uniform Code of Military Justice – rules for conducting trials and other judicial matters within the US armed forces – bar the president from establishing military commissions with fewer procedural safeguards than are afforded to American soldiers charged with crimes.
At the same time the majority justices adopted a narrow view of the Congress's 2001 Authorization for the Use of Military Force. The administration had argued that the AUMF authorized more than just military operations, it also authorized military detentions and special military trials.