WASHINGTON — Valerie Plame, the former CIA officer at the heart of a four-year political furor over the Bush administration's leak of her identity, lashed out Friday at the White House, testifying in Congress that the president's aides destroyed a career she loved and slipped her name to reporters for "purely political motives."

Plame, speaking publicly about the case for the first time, contended that her name and job "were carelessly and recklessly abused" by the government. Although she and her colleagues knew that "we might be exposed and threatened by foreign enemies," she said, "it was a terrible irony that administration officials were the ones who destroyed my cover."

Plame calmly but firmly knocked down longstanding claims by administration allies that the disclosure was not criminal because she had not worked in a covert capacity.

"I am here to say I was a covert officer of the Central Intelligence Agency," Plame told House members, journalists and a smattering of antiwar activists. Her work, she said, "was not common knowledge on the Georgetown cocktail circuit."

Plame also provided the most detailed account to date of her role in a decision by the agency to dispatch her husband, former U.S. Ambassador Joseph Wilson, to Niger five years ago to assess reports that Iraq had sought to buy nuclear material from the African nation.

Rebutting an assertion by White House officials to reporters that she had sent her husband on the trip, Plame said one of her colleagues broached the idea after a call in early 2002 from Vice President Cheney's office seeking information about Iraqi activity in Niger. Plame said she "wasn't overjoyed" at the suggestion because a trip would leave her alone with their 2-year-old twins.

Still, she said, at the direction of her supervisor, she asked her husband whether he would come to CIA headquarters at suburban Langley, Va., to discuss the possible trip and sent a quick e-mail about the prospect to the chief of the agency's counterproliferation division, where she worked.

"I did not suggest him," she said. "There was no nepotism involved. I didn't have the authority."

Plame's poised, two-hour turn at the witness table, in the marbled hearing room of the House Oversight and Government Reform Committee, was a theatrical sequel to the lengthy trial of Cheney's former chief of staff, Lewis "Scooter" Libby, which ended last week. Libby was convicted of four felonies for lying to FBI agents and a federal grand jury about his role in disclosing Plame's identity.

Her presence on Capitol Hill was part of a hearing called to examine the White House's handling of classified information, but it largely allowed committee Democrats to flog President Bush and his aides with her testimony. They also accused the White House of a national security violation and of failing to conduct an internal investigation of the leak, as Bush once promised.

The panel's chairman, Rep. Henry Waxman, D-Calif., portrayed Plame as a hero betrayed by her government. "They made you collateral damage," Waxman said. "Your career was ended. Your life may have been in jeopardy, and they didn't seem to care."

The committee's ranking Republican, Rep. Tom Davis, Va., sought to deflect blame from the administration. "This looks to me more like a CIA problem than a White House problem," Davis said. The agency should have made sure that White House officials who inquired about Plame knew that her position was classified, he said.

A few months after the Iraq war began in 2003, Plame was drawn into a maelstrom as the White House struggled with the stirrings of opposition to the invasion. In July 2003, Wilson published an op-ed column that accused the president of distorting the findings of the Niger mission: that there was no evidence Iraq had recently sought to buy yellowcake uranium there for a nuclear weapons program. On July 14, 2003, Plame was identified in a syndicated column by Robert D. Novak.

Testimony at Libby's trial made it clear that Cheney and other senior administration officials and their aides worked aggressively to discredit Wilson. Prosecutors said Libby, then Cheney's chief of staff, and other officials told journalists about Plame to insinuate that Wilson was chosen for the CIA mission solely because of their relationship.

In fact, Plame said Friday, her husband "had already gone on some CIA missions previously to deal with other nuclear matters." That, she said, is why her colleague "suggested, 'Well, why don't we send Joe?' " Plame, 43, appeared on Capitol Hill without Wilson, who has been as voluble criticizing the leak and the administration as Plame has been silent. Her sole public comment until Friday was a six-sentence statement she read when the couple appeared last summer at the National Press Club after filing a lawsuit against officials including Libby, Cheney and Karl Rove, the president's top political adviser.

She also posed with her husband for a photograph in Vanity Fair magazine — a move she described Friday as "more trouble than it was worth," adding, "Having lived most of my life very much under the radar, my learning curve was steep."

Plame's testimony on the covert nature of her job was buttressed by a statement that Waxman read at the hearing's opening which, he said, was approved by Gen. Michael Hayden, the CIA's director. The statement said that Plame worked in a covert capacity at the time of Novak's column and that her employment status was classified under an executive order.

Saying she could reveal only limited information about her former job, Plame testified that, just before the Iraq war, she was "still a covert officer" working to "discover solid intelligence for senior policymakers on Iraq's presumed weapons-of-mass-destruction program" and that she "traveled to foreign countries on secret missions to find vital intelligence."

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