Narratives matter -- stories that make sense of the messy realities of the world, that connect cause with effect, that have a beginning, middle and end. We seek to understand the struggle in Iraq by constructing narratives and fitting events into them. But sometimes a narrative is undercut and rendered inoperative by emerging facts. And sometimes a new narrative emerges when facts previously unknown come to light. Both happened in the past two weeks.

The narrative that was undercut was the claim by Joseph Wilson that the Bush White House had breached national security by disclosing the identity of his wife to reporters.

This was supposedly done to discredit Wilson's July 2003 New York Times article, in which he said he had debunked George W. Bush's claim that Iraq was trying to obtain uranium in Africa. The Wilson claim helped to embed the "Bush lied, people died" theme in public discourse.

It has long since come out that just about everything Wilson said was false. He was not, as he suggested, sent on his mission to Niger by Dick Cheney. He was recommended for the trip, contrary to his denial, by his wife, CIA employee Valerie Plame. He reported to the CIA that an Iraqi official had come to Niger on a trade mission in 1999 -- evidence that tended to confirm rather than refute the British intelligence claim that Iraq was uranium-shopping in Africa -- a claim that Britain's Lord Butler judged "well founded."

Now come Newsweek's Michael Isikoff and the Nation's David Corn with a new book disclosing that it was not Karl Rove who first disclosed Plame's name to reporter Robert Novak. It was Richard Armitage, deputy secretary of state, and a skeptic about, if not an opponent of, military action in Iraq. Interestingly, Justice Department officials knew this even before Patrick Fitzgerald was named a special prosecutor. And they knew, as Corn has admitted, that Plame had not worked overseas within five years of her name's disclosure, which meant that she was not covered by the Intelligence Identities Protection Act.

Yet for more than two years, Fitzgerald investigated Rove and other White House aides and indicted one for providing false testimony. All this, even though it was clear there was no underlying crime.

The Wilson-Plame narrative obscured the fact that Bush did not lie. Given Saddam's history of WMD development and use, given his successful attempts to obstruct inspection, any responsible American president had to assume that he had WMDs. Bill Clinton so assumed in 1998. George W. Bush so assumed in 2003. The record of Saddam's deeds left them no choice.

It is said our intelligence was faulty. But what intelligence evidence could have convinced a responsible president that Saddam had no WMDs? Fresh facts. The new narrative that emerged last week was provided by Bush in his Sept. 6 speech in which he urged the authorization of military tribunals to try suspected terrorists. In vivid detail, he told stories we had not heard before: of how under CIA interrogation Abu Zubaydah fingered Khalid Shaikh Mohammed, mastermind of the Sept. 11 attacks, and led us to apprehend terrorists planning more attacks; how KSM identified al-Qaida operatives in Southeast Asia and a terrorist who was plotting anthrax attacks in the United States; how other terrorists enabled us to foil attacks on the U.S. consulate in Karachi and a U.S. Marine base in Djibouti.

The debate on what to do about captured terrorists has taken place largely in the courts and has been conducted by lawyers whose default assumption seems to be that unlawful combatants should be entitled to all the protections given criminal defendants in domestic courts.

Arguments are made that defendants, not just their lawyers, should have access to secret evidence and that they should get Geneva Convention protections though they are classed as unlawful combatants under those conventions. Bush's narrative gives us reason to think about the consequences of indulging such abstract concerns. Consequences like what we saw on Sept. 11.

The collapse of the Wilson-Plame narrative leaves troubling questions about the Fitzgerald investigation -- and the media that cheered it on. The emerging narrative of foiled terrorist plots puts the issue squarely before Congress: whether it should prohibit practices that have successfully protected us against terrorist attacks.