WASHINGTON, July 15 - A federal appeals court ruled unanimously on Friday that the military could resume war crimes trials of terrorism suspects at Guantánamo Bay, Cuba, which were suspended last year.
The decision, by a three-judge panel of the United States Court of Appeals for the District of Columbia Circuit, reversed a lower court's ruling that abruptly halted the first war crimes trials conducted by the United States since the aftermath of World War II. The appeals judges said the Bush administration's plan to try some detainees before military commissions did not violate the Constitution, international law or American military law.
Their ruling, in the case of Salim Ahmed Hamdan, a driver for Osama bin Laden, was a significant legal victory for the administration, which has found itself engaged in several court battles over tools that officials say they need to fight terrorist groups.
"The president's authority under the laws of our nation to try enemy combatants is a vital part of the global war on terror," Attorney General Alberto R. Gonzales said on Friday, "and today's decision reaffirms this critical authority."
Neal K. Katyal, a Georgetown University law professor who represented Mr. Hamdan, said he would consider an appeal.
"Today's ruling," Mr. Katyal said, "places absolute trust in the president, unchecked by the Constitution, statutes of Congress and longstanding treaties ratified by the Senate of the United States."
He noted that many retired senior officers who had signed a brief supporting his position maintained that the way detainees at Guantánamo had been treated imperiled American troops who might themselves be captured on the battlefield.
Military officials have said in recent weeks that they are eager and ready to resume the trial of Mr. Hamdan. At a Senate hearing on Thursday, Brig. Gen. Thomas L. Hemingway, the Air Force officer who supervises the military commission process, and Daniel J. Dell'Orto, the Pentagon's principal deputy general counsel, both said they expected war crimes trials to resume within 30 to 45 days if the appeals court ruled in their favor.
Of more than 500 detainees remaining at Guantánamo, Mr. Hamdan is one of four who have so far been charged with war crimes. Twelve others have been designated by President Bush as eligible for trial, and military officials have suggested that they are prepared to bring charges against dozens of other prisoners there should the president designate them as well.
Mr. Hamdan, a 35-year-old Yemeni who was captured in Afghanistan, is charged with conspiracy to commit attacks on civilians, murder and terrorism. He has argued through his lawyers that although he served as a driver for Mr. bin Laden, he was not a member of Al Qaeda and never took up arms against Americans or their allies. He was sitting in a Guantánamo courtroom when the proceedings in his case were suddenly halted Nov. 8 by the earlier court decision, issued by James Robertson, a federal district judge in Washington.
Judge Robertson ruled that the military commissions violated the Geneva Conventions, the principal international laws of war, to which the United States is a signatory; violated the Constitution, because, he said, the president did not have the necessary authority from Congress; and violated the Uniform Code of Military Justice, which, he said, requires that detainees be tried under the same conditions as American soldiers who are court-martialed.
In Friday's decision, written by Judge A. Raymond Randolph, the appeals court rejected all three rationales, with occasionally disdainful language.
The court said it was well established that the Geneva Conventions "do not create judicially enforceable rights" - that is, accusations of a violation may not be brought in a lawsuit.
The appeals panel also held that Judge Robertson had been incorrect in maintaining that Congress had not authorized Mr. Bush to set up the commissions. Congress gave him the authority to do so, the panel said, in three resolutions dealing with terrorism. In one, the lawmakers authorized the president "to use all necessary and appropriate force" against anyone who had abetted the Sept. 11 attacks, and granted him the authority to act to prevent international acts of terrorism.
In addition, the appeals court said the commissions were not bound by the rules of courts-martial, like allowing for defendants to be present at all times. In the earlier decision, Judge Robertson noted that Mr. Hamdan had been excluded from the Guantánamo courtroom for some of the proceedings after the military commission's chief judge ruled that classified information was likely to be exposed.
The three judges who issued the ruling were all nominated to the bench by Republican presidents. Judge Randolph, chosen by the first President Bush, was joined in the decision by Judges John Roberts, nominated by the current president, and Stephen F. Williams, by President Ronald Reagan. Judge Robertson, of the lower court, was nominated by President Bill Clinton.
The war crimes commissions are one of three types of legal bodies created by the military to deal with detainees at Guantánamo.
The first, called combatant status review tribunals, made up of three-officer panels, considered the cases of all the detainees to determine if they had been properly deemed unlawful enemy combatants, who, the military said, could be held there indefinitely. Those tribunals found that all but 33 of more than 560 detainees then at Guantánamo had been properly imprisoned.
This year, the military began a second set of proceedings for the remaining detainees, now numbering about 520. In these proceedings, before "administrative review boards," panels of three officers are asked to determine if the detainee is no longer a threat and thus may be eligible for release. No figures from those deliberations have been announced.
Separately, nearly 200 of the Guantánamo prisoners are represented in lawsuits in federal court. Those actions were made possible by a Supreme Court ruling in June 2004 that detainees could use the civilian court system to challenge their imprisonment.
