In speeches, Mr. Cheney has made little secret of his view that Congress impinged on presidential powers after Vietnam, Watergate and the intelligence scandals of the 1970’s and 1980’s, and that he was determined to reverse the trend.

As recently as last month he was still advocating that view. In a letter to Senator Arlen Specter, the Pennsylvania Republican who is chairman of the Senate Judiciary Committee, Mr. Cheney insisted that there was no need for legislation to carry out the domestic spying operation after its existence was revealed in The New York Times.

From the morning after that article was published, Attorney General Alberto Gonzales Jr. and General Michael V. Hayden, who has since been appointed the director of the Central Intelligence Agency, argued vociferously that the president already had all the authority he needed to order the wiretapping program without court approval.

At other moments, Mr. Gonzales has mentioned what may have been the real reason that the Bush administration sidelined Congress: It believed that to seek permission to conduct domestic wiretapping would expose a covert program.

“There was some consideration” about seeking legislation, Mr. Gonzales told the House Judiciary Committee in April, but “ultimately there was a collective agreement that that would not be possible without compromising the effectiveness of the program.”

Now, some administration officials say that strategy may have been flawed. “It puts you at the mercy of what gets leaked,” said one senior official who requested anonymity because he was discussing internal business of the White House. The military tribunals were a different issue, one driven by a defeat at the Supreme Court.

As early as late 2001, the issue of how to treat detainees became a subject of heated debate inside the White House. Secretary of State Colin L. Powell argued that the White House had to acknowledge that international law, not the administration’s desires, had to govern how fighters were treated, even if they were not in uniform and represented no legitimate government. To do otherwise, said Mr. Powell, a former chairman of the joint chiefs of staff, would be to invite the mistreatment of captured American soldiers.