President Bush cannot order the military to indefinitely imprison a suspected al-Qaeda operative as an "enemy combatant," a court ruled last night.
The 2-1 appellate ruling was a major setback for Mr Bush's contention in the "war on terrorism" that he has the power to detain people in the United States without charging them.
The court panel based in Richmond, Virginia, ruled that the Qatari national involved, Ali Saleh Kahlah al-Marri, must be released from military custody. "The decision protects legal residents and citizens from secret detention," said Mr al-Marri's lawyer.
In the case of Mr al-Marri, held in a US Navy brig in Charleston, South Carolina, for about four years without charges, Judge Diana Gribbon Motz made a clear distinction for suspects being held in the United States.
"The government cannot subject al-Marri to indefinite military detention. For in the United States, the military cannot seize and imprison civilians - let alone imprison them indefinitely," she said.
The government could still transfer him to civilian authorities to face criminal charges, initiate deportation proceedings, hold him as a witness in a grand jury case or detain him for a limited period under the Patriot Act, an anti-terrorism law.
The ruling followed last week's dismissal of charges against two suspects at the US prison at Guantánamo Bay in Cuba.
The Pentagon is asking for reconsideration of the rulings that two were being held in the controversial prison because they were designated only as "enemy combatants," and not "unlawful enemy combatants" as required by a 2006 law crafted after earlier definitions were rejected.