ACCOUNTABILITY is one of those ideals, like justice or the triumph of right over might, that are wonderful in principle but usually disappointing in practice.

This is nowhere more true than in Washington, where one of the most powerful men in President Bush's inner circle, a man who helped conceive, plan and execute the Iraq war, has managed to escape scrutiny for steering his country into one of the greatest strategic catastrophes of his generation.

I am referring, although nobody else does, to Paul Wolfowitz. Remember Wolfowitz, best known to readers of this and other newspapers as the "chief architect of the Iraq war"? Before the war, he was hailed by many as one of the great foreign policy intellectuals of our time. He was a leading defense strategist, a former U.S. ambassador to Indonesia and the former dean of the School of Advanced Studies at Johns Hopkins University, a man whose views on democracy and the Middle East were taken seriously by both his admirers and his critics. In 2001, Wolfowitz, then 58, was named deputy secretary of Defense, serving as top aide to Secretary Donald H. Rumsfeld.

Yet today, as the policies he put in place come crashing down, Wolfowitz is nowhere to be found — at least not at the Pentagon. In fact, he left in 2005 to become president of the World Bank, where he has been busy trying to save Africa. In seeking refuge at the World Bank, Wolfowitz has followed in the footsteps of Robert McNamara, President Johnson's Vietnam War-era Defense secretary. McNamara was the "architect" of the Vietnam War in his own time, but he bailed out of the Pentagon to run the World Bank in 1968 as the U.S. body count mounted.

What is particularly disturbing is that Wolfowitz is visibly delighting in his role as one of the world's highest-profile (publicly funded) philanthropists — while saying barely a word about the catastrophe in Iraq. In the few comments he has been badgered into making about the war since he left the Pentagon, he has defended the conduct of the U.S. and expressed the belief that Iraqis will struggle their way to freedom.

He has insisted that the subject of Iraq rarely comes up in his new job, where people would rather hear his plans for Africa. How convenient to be required to read proposals for breaking the poverty cycle instead of the morning casualty reports that blight each daybreak at the Pentagon.

I invited Wolfowitz to comment, telling us his views on Iraq or the problem of democracy in the radicalized Middle East. He declined, but e-mailed this response: "I'm not a U.S. official any more and unfortunately not a private citizen either. I work for 184 countries that expect me to do the job at the World Bank. I would like nothing better than to be able to get involved in this debate [over Iraq]. I would particularly like to be able to clear the record of some of the garbage about myself personally, but if I start doing that, the people I work for would say, 'You are not doing your job, you are getting mixed up in something that is a distraction from the message that we would like you to deliver.' I have spoken to heads of 11 African countries, I have spoken to ordinary people, I have spoken to civil society groups; none of them care about my role in Iraq, they care about what I do in the World Bank."

Is that a reasonable answer? It's true that the bank's international board probably would prefer that Wolfowitz stick to saving Africa. But is that an excuse for him to keep silent while his country is agonizing over how Iraq went so wrong?

Earlier this month, Wolfowitz was heckled during a speech in Atlanta. One protester called him a war criminal. That's silly. But it is true that the brilliant and idealistic advisor, in large part through the force of his ideas, played a big part in selling the war to his bosses, and eventually to the American people.

To his credit, Wolfowitz had argued for years that the U.S. policy of cooperating with repressive regimes in the Middle East was a grave mistake, that democracy and freedom were not American values but universal aspirations. His principled opposition to tyranny in any form won him many admirers — as well as the respect of people who disagreed with him on some issues but believed his ideas posed a moral challenge that could not be ignored.

Wolfowitz also believed the U.S. had erred in allowing Saddam Hussein to stay in power after the dictator ravaged Kuwait in 1990. And he continued to advocate for Hussein's overthrow. Sept. 11 revived his aging arguments. According to Bob Woodward, when Bush's senior advisors assembled at Camp David just days after the 9/11 attacks, Wolfowitz was the only one who advocated military action against Iraq as a first response.

In Woodward's book, Wolfowitz is shown criticizing some aspects of Rumsfeld's conduct of the war. Yet some of the most fundamental misjudgments of Iraq appear to have been his as well. He testified to Congress, for instance, that U.S. troops were more likely to be treated as liberators than occupiers, and that Iraq's own wealth would likely suffice to pay for most of its reconstruction. He dismissed warnings that ethnic strife could erupt in a democratic or chaotic Iraq, saying that most of the violence in Iraq had always been by the Hussein regime against various ethnic groups. And his promotion of the now-discredited Ahmad Chalabi has never been explained.

In February 2003, on the eve of the invasion, before the House Budget Committee, he heaped scorn on "the notion that it will take several hundred thousand U.S. troops to provide stability in post-Saddam Iraq," saying that the number was "wildly off the mark."

Of course, plenty of other smart people also got Iraq wrong, so why single out Wolfowitz? Because from Bush on down, the politicians are being held accountable. Iraq has destroyed the Bush legacy. Generals have seen their military wounded. The war has tarnished Colin Powell's once-shining reputation, destroyed Rumsfeld's and killed any shot Condoleezza Rice might have had at the White House. But Wolfowitz has failed up, into one of the world's most prestigious jobs. "I'll have a chance sometime to talk about Iraq," Wolfowitz said in his e-mail last week. "But it's a distraction and a harmful distraction from what I'm trying to accomplish for Africa and the developing world."

Still, as a man whose reputation for intellectual honesty helped land him the World Bank job, the cerebral Wolfowitz owes the American people not only an explanation but also his best forensic analysis of mistakes made and how not to repeat them. Does he believe democracy can be promoted in any real sense when the Middle East is on fire? Under his stewardship, the World Bank is stepping up lending in Iraq, so these questions are not entirely academic.

If Wolfowitz still believes that the decision to go to war was correct and that more reconstruction money can still save Iraq, then this is a critical time to explain why. If he believes he erred, he should help us understand how it happened and why — and he should apologize, as a private citizen. A World Bank job — or any other important post — should not shield him from accountability.