In a remarkable decision issued today, the U.S. Supreme Court ruled that Guantanamo Bay alien detainees have a right to challenge the lawfulness of their detentions in U.S. federal courts. The 5-4 decision was issued in the combined cases of Al Odah v. United States and Boumediene v. Bush.

In its decision, the Court ruled that Congress had not validly suspended habeas corpus. Under Article I, Section 9, Clause 2 of the Constitution, the writ of habeas corpus may only be suspended in times of rebellion or invasion -- neither of which have occurred. 

Just as significantly, the Court also ruled that the alternative to habeas corpus that Congress set up in 2005 under the Detainee Treatment Act, which only permits detainees to challenge the lawfulness of their detentions under very restrictive and limited terms, is an inadequate and ineffective alternative to habeas. The DTA, according to the Court, did not provide sufficient legal protections to detainees who sought to challenge their detentions under the DTA scheme.