A top Defense Department official appeared before the Senate Armed Services Committee to defend the Bush administration's controversial plans to set up military tribunals to try foreign terrorists.

Deputy Defense Secretary Paul Wolfowitz is quick to point out that military justice authorities are still working out details of the process that will be following by the tribunals.

Mr. Wolfowitz also stresses that President Bush has not yet designated any suspects to be tried by such special military panels.

But he told the Senate committee there are historical precedents that, in the administration's view, are relevant. "During and following World War II, we did not bring German and Japanese war criminals to the United States for trial in civilian courts, we tried them by military commissions," he said.

Mr. Wolfowitz also argued there are special advantages to using military tribunals, including speedier trials, safeguards for sensitive evidence, and a more secure process than possible in civilian courts. By using these tribunals, he argued, "we can better protect civilian judges, jurors, and courts from terrorist threats and assure the security of the trial itself."

The notion of military tribunals has drawn some criticism from civil-rights groups fearful that individual liberties may be jeopardized.

But while the ground rules are not yet set, Mr. Wolfowitz suggests foreign terrorist suspects do not deserve the same kinds of legal protections that would, for example, bar evidence deemed taken by police in an illegal search.

"Imagine if a foreign terrorist were sneaking into the United States with a trunkload of anthrax in the back of the car and a policeman unreasonably opened the trunk and found it," suggested Mr. Wolfowitz. "I do not think we would want that evidence excluded in a trial, and that might be a reason why you would consider a different criminal procedure."

Members of the Senate Armed Services committee voiced few concerns about the administration's plans during the hearing. But during one exchange with Mr. Wolfowitz, Senator Edward Kennedy questioned whether some foreign governments might seize on the U.S. military tribunal to justify their own secret military trials. "I think that is one of the reasons why we want to work out very carefully the kinds of procedures that will make the judgments of any military commission that we establish meet a full standard of fairness," responded Mr. Wolfowitz.

Defense Secretary Donald Rumsfeld has said the main suspects the United States hopes to capture and possibly bring before a military tribunal are senior leaders of the al-Qaida terrorist network.

But most have eluded capture in Afghanistan, though some have been killed in the fighting.