“The president has ample constitutional and statutory authority to deploy the military against international or foreign terrorists operating within the United States ,” the memorandum said.

The memorandum — written by the lawyers John C. Yoo and Robert J. Delahunty — was directed to Alberto R. Gonzales , then the White House counsel, who had asked the department about a president’s authority to use the military to combat terrorist activities in the United States.

The memorandum was declassified in March. But the White House debate about the Lackawanna group is the first evidence that top American officials, after the attacks of Sept. 11, 2001, actually considered using the document to justify deploying the military into an American town to make arrests.

Most former officials interviewed for this article spoke only on the condition of anonymity because the deliberations about the case involved classified information. They agreed to talk about the internal discussions only after the memorandum was released earlier this year.

New information has recently emerged about the deliberations and divisions in the administration over some of the most controversial policies after the Sept. 11 attacks, like the decision to use brutal interrogation methods on Qaeda detainees.

Former officials in the administration said this debate was not as bitter as others during Mr. Bush’s first term. The discussions did not proceed far enough to put military units on alert.

Still, at least one high-level meeting was convened to debate the issue, at which several top Bush aides argued firmly against the proposal to use the military, advanced by Mr. Cheney, his legal adviser David S. Addington and some senior Defense Department officials.

Advertisement Continue reading the main story

Among those in opposition were Condoleezza Rice , then the national security adviser; John B. Bellinger III, the top lawyer at the National Security Council ; Robert S. Mueller III , the director of the Federal Bureau of Investigation ; and Michael Chertoff , then the head of the Justice Department’s criminal division.

“Frankly, it was a bit of a turf war,” said one former senior administration official. “For a number of people, crossing the line of having intelligence or military activities inside the United States was not worth the risk.”

Mr. Bush ended up ordering the F.B.I. to make the arrests in Lackawanna, near Buffalo, where the agency had been monitoring a group of Yemeni Americans with suspected Qaeda ties. The five men arrested there in September 2002, and a sixth arrested nearly simultaneously in Bahrain , pleaded guilty to terrorism-related charges.

Newsletter Sign Up Continue reading the main story Please verify you're not a robot by clicking the box. Invalid email address. Please re-enter. You must select a newsletter to subscribe to. Sign Up You will receive emails containing news content , updates and promotions from The New York Times. You may opt-out at any time. You agree to receive occasional updates and special offers for The New York Times's products and services. Thank you for subscribing. An error has occurred. Please try again later. View all New York Times newsletters.

Scott L. Silliman, a Duke University law professor specializing in national security law, said an American president had not deployed the active-duty military on domestic soil in a law enforcement capacity, without specific statutory authority, since the Civil War.

Senior military officials were never consulted, former officials said. Richard B. Myers , a retired general who was chairman of the Joint Chiefs of Staff , said in a recent interview that he was unaware of the discussion.

Former officials said the 2002 debate arose partly from Justice Department concerns that there might not be enough evidence to arrest and successfully prosecute the suspects in Lackawanna. Mr. Cheney, the officials said, had argued that the administration would need a lower threshold of evidence to declare them enemy combatants and keep them in military custody.

Earlier that summer, the administration designated Jose Padilla an enemy combatant and sent him to a military brig in South Carolina . Mr. Padilla was arrested by civilian agencies on suspicion of plotting an attack using a radioactive bomb.

Those who advocated using the military to arrest the Lackawanna group had legal ammunition: the memorandum by Mr. Yoo and Mr. Delahunty.

The lawyers, in the Justice Department’s Office of Legal Counsel, wrote that the Constitution, the courts and Congress had recognized a president’s authority “to take military actions, domestic as well as foreign, if he determines such actions to be necessary to respond to the terrorist attacks upon the United States on Sept. 11, 2001, and before.”

Advertisement Continue reading the main story

The document added that the neither the Posse Comitatus Act nor the Fourth Amendment tied a president’s hands.

Despite this guidance, some Bush aides bristled at the prospect of troops descending on an American suburb to arrest terrorism suspects.

“What would it look like to have the American military go into an American town and knock on people’s door?” said a second former official in the debate.

Chief James L. Michel of the Lackawanna police agreed. “If we had tanks rolling down the streets of our city,” Chief Michel said, “we would have had pandemonium down here.”

The Lackawanna case was the first after the Sept. 11 attacks in which American intelligence and law enforcement operatives believed they had dismantled a Qaeda cell in the United States.

In the months before the arrests, Mr. Bush was regularly briefed on the case by Mr. Mueller of the F.B.I. and George J. Tenet , the director of central intelligence. The C.I.A. had been tracking the overseas contacts of the Lackawanna group.