The Wilsons have had a low-key social life, friends say. Mr. Wilson said they had attended only one "A-list Washington party," given by Ben Bradlee, the retired Washington Post editor. Before July 2003, some neighbors knew them from the playground only as "Trevor and Samantha's mom and dad."
Their turn in the limelight changed that temporarily, as liberal celebrities embraced them; they were honored in late 2003 at a dinner at the guesthouse of the television producer Norman Lear, with guest list that included Warren Beatty.
The couple's actions in 2002 have become, in the polarized politics of the Iraq war, subject to divergent interpretation. All agree that Mr. Wilson traveled to Niger in February 2002 at the C.I.A.'s request to assess reports that Saddam Hussein had tried to buy uranium there. There the agreement ends.
In the version of his Republican critics, laid out in part by members of the Senate Intelligence Committee last year, Mr. Wilson's trip was a junket orchestrated by his wife. Further, the critics say, Mr. Wilson's findings on the uranium question were equivocal. But as a partisan Democrat, they say, he exploited his minor involvement to attack the president, asserting that Mr. Bush misled the American people by citing the questionable uranium claim in his 2003 State of the Union address.
Mr. Wilson has laid out his own account in interviews and in his memoir, "The Politics of Truth: Inside the Lies That Led to War and Betrayed My Wife's C.I.A. Identity." The 514-page book, which features on the back cover photographs of Mr. Wilson with the first President Bush, President Bill Clinton and Saddam Hussein, has sold 60,000 copies in hardcover, according to the publisher, Carroll & Graf. The just-published paperback includes an 11,000-word essay by Russ Hoyle, an investigative reporter recruited by Carroll & Graf to examine factual disputes raised by the case.
Mr. Wilson said that though his wife wrote a memorandum describing his expertise at the request of a C.I.A. superior, she did not propose him for the Niger trip. He scoffs at the notion that a trip to one of the poorest countries on earth, for which he was paid only his expenses, was some kind of prize.
He has acknowledged he may have misspoken about a few details, like the date he became aware of forged documents purporting to show a uranium sale. But conservatives' attacks on his credibility, he said, are merely an effort to distract Americans from a far graver fact: that the United States went to war on the basis of flimsy, distorted evidence.
"I'm deeply saddened that the debate before the war did not adequately take into consideration issues that a number of us had raised," Mr. Wilson said.
While his wife has shunned publicity, he has become an always-available news media voice, lending the weight of international experience and insider status to criticism of Mr. Bush's conduct of the war.
Despite conservatives' efforts to portray him as a left-wing extremist, he insisted he remained a centrist at heart. But after his tangle with the current administration, he admits "it will be a cold day in hell before I vote for a Republican, even for dog catcher."
Mr. Wilson ended a long interview in a downtown hotel when he realized he was late to pick up the twins. As the first gulf war loomed, and Mr. Wilson was the last American official to meet with Saddam Hussein, his older twins, Joe and Sabrina, were 12 years old, and worried that their father might not make it out of Baghdad to join them in the United States, he said.