A special three-member review panel, including one military judge, will hear appeals, which can get a final review by the President. There will be no independent appeals before federal courts.
"Let there be no doubt: Commissions will conduct trials that are fair and impartial," said Rumsfeld, as he presented a 16-page set of rules and procedures. "This is an exceedingly important subject, and it's important for our country that we do it right."
Rumsfeld and other Pentagon officials said the tribunals constituted a rare legal tool, not used since World War II, to prosecute alleged terrorists swiftly and safely while continuing to interrogate detainees and uncover plots of future attacks.
"This war is going to go on for a long time, and we want to make sure that these proceedings . . . do not interfere with our war effort and may actually assist us in promoting our war aims," said Douglas Feith, undersecretary of defense.
The limited appeals process drew some criticism from legal groups.
"The administration is assuring us that the trials will be fair and therefore no truly independent review is necessary," said Elisa Massimino, director of the Washington office of the Lawyers Committee for Human Rights. "Experience tells us otherwise - no system is perfect and independent review is essential."
Officials left several questions, including the timetable and location for trials. Rumsfeld said there were "no candidates yet to be tried" before a tribunal. He called it "an option" that may be used sparingly.
Military officials have said they hope the prospect of tribunals encourages cooperation from detainees being held at Guantanamo Bay Naval Base in Cuba.
The rules grew out of a four-month debate inside and outside the government over how to prosecute al-Qaeda leaders and fighters and Taliban soldiers captured on the Afghan battlefield or elsewhere. The U.S. military is holding 300 detainees in Guantanamo Bay and more than 200 in Afghanistan.
The rules are a response to legal, congressional and international criticism of President Bush's Nov. 13 order establishing the framework for military trials. Bush's order, for example, required a two-thirds vote to sentence a defendant to death. The new rules require unanimity.
Military trials will resemble courts-martial, with a two-thirds vote required to convict, but there are distinctions: the relaxed standard of evidence and no recognized appeal outside the military judicial system.
General Counsel William Haynes tried to lay the groundwork for keeping some detainees in lengthy, indefinite detention. Many detainees are regarded as dangerous, but evidence against them is sketchy and they may never be charged. Others may eventually be returned to their home countries.
"When somebody's trying to kill you and your people and you capture them, you can hold them," Haynes said. "Questions of speedy trial do not apply. We may hold enemy combatants for the duration of the conflict.
"The conflict is still going and we don't see an end in sight right now," he added.
A former military lawyer said he was "dumbfounded by the notion" of lengthy detention without any decision on a detainee's legal status.
"I don't think you can hold someone indefinitely, and that's going to be a problem if they try to do that," said Scott Silliman, a former senior attorney in the Air Force.
Silliman also predicted that Guantanamo would be the site for tribunals. It's not on U.S. soil and "would make it very difficult to trigger a habeas corpus review" by a lawyer seeking the jurisdiction of a federal court, he said.
Contact Frank Davies at 202-383-6054 or firstname.lastname@example.org.