Ms. Wilson's identity was first disclosed in a news column by Robert Novak on July 14, 2003, just days after her husband had written a commentary in The New York Times asserting that the Bush administration had distorted intelligence to build the case for invading Iraq.

Mr. Wilson, a former ambassador, had accused the Bush White House of knowingly distorting intelligence about Iraq's efforts to obtain material for its nuclear program in order to bolster the case for going to war.

For Mr. Fitzgerald, the evidence was a yes-or-no affair: Mr. Libby lied under oath about his knowledge of Valerie Wilson, an undercover C.I.A. officer whose husband, Joseph C. Wilson IV, had accused the Bush administration of distorting prewar intelligence.

"I told them that ideology distorts intelligence and that during the cold war they ended up being seen by the world at large as spoilers," Mr. Mailer said in an interview.

"As an historian, I'm glad to have the material out there," said John Prados, who has written books on national security, including one that accuses the administration of distorting prewar intelligence.

In his closing argument, Patrick J. Fitzgerald, the chief prosecutor, said that disclosure of Ms. Wilson's identity was used by the White House to discredit her husband's assertions that the Bush administration had distorted intelligence to justify invading Iraq.

Libby mentioned the Wilsons while complaining to the C.I.A. that some of its analysts had been griping to reporters about being pressured into distorting intelligence during his and Cheney's frequent prewar visits to the agency.

The special prosecutor in the case, Patrick J. Fitzgerald, investigated whether the leak was part of an effort to retaliate against Ms. Wilson's husband, Joseph C. Wilson IV, a former ambassador who had accused the Bush administration of distorting intelligence before the war in Iraq.

He said he believed that it would be his obligation as an intelligence officer "to throw your body onto the rails" to prevent policy makers from seeking to impose political judgments on the intelligence process or distort intelligence for political purposes.

In his appearance before the Hutton inquiry, Mr. Blair said he had considered the charge that he had distorted intelligence so damaging to his integrity that he would have had to resign had it been true.