WASHINGTON, 25 March 2004 — Richard Clarke has published a devastating critique of George W. Bush’s national-security policy. Of course, the allegations might not be the whole story, because lots of other people have their stories, too. So it’s a good thing that we have an ongoing investigation, in which people could go to jail if they lie.

In a bombshell appearance on “60 Minutes’’ Sunday night, Clarke set forth the three arguments in his new book, “Against All Enemies.’’

First, he asserts that the administration “ignored’’ the threat from Al-Qaeda right up to Sept. 11. Second, he argues that even after the attack from Osama Bin Laden’s forces, many in the administration wanted to ignore Bin Laden’s hide-out in Afghanistan and go after Iraq instead. Indeed, Clarke continues, the administration wrongly targeted Iraq, which had nothing to do with Sept. 11. Third, the president, having done a “terrible job’’ prosecuting the war on terrorism, now seeks to be re-elected by shamelessly spinning a three-year record of incompetence and distortion.

That’s quite a litany of accusations, but they must be considered in three different lights.

The first light should shine down on Clarke’s motivations. Having worked as a civil servant for 30 years, he resigns from the government in 2003. He spends the next year writing this tell-all book, published less than eight months before the presidential election.

Why is Clarke doing it? Is he seeking revenge on Bush the 43rd’s people, who demoted him in 2001 after he’d been working the anti-terrorism beat at the White House for a decade? Is he trying to whip up a controversy to achieve best-sellerdom? Is he “auditioning’’ for a job with a hypothetical President John Kerry, as one Bush adviser put it? Or, alternatively, is he what he says he is — an “outraged’’ citizen, free to speak out against this malignant administration?

In any case, the White House has come down hard on its former employee: “Dick Clarke just does not know what he is talking about,’’ snaps National Security Adviser Condoleezza Rice, about whom Clarke is harsh.

But, of course, the second light should shine down on the Bush people’s motivations. All the president’s men and women have been good at offering general denials and denunciations of Clarke, but not so good at the point-by-point rebuttals. For example, Clarke claims that Bush personally leaned on him to, in effect, manufacture evidence against Iraq. The White House says that the president can’t recall such a meeting, and besides, its records show that Bush wasn’t where Clarke said he was. However, one senses lawyering in that crafted answer.

Yet a third light should shine down on the motivations of all Clinton-administration alumni, including Clarke. Did President Bill Clinton do everything he could to smash Al-Qaeda in the 1990s? The record seems to show that he didn’t do much, but of late Clinton loyalists seem bent on upwardly revising that record.

A story on the front page of Saturday’s New York Times stated that outgoing Clintonians “repeatedly warned’’ the incoming Bushites about the threat from Al-Qaeda. Yet the Times story is two-years stale; it is recycled from an article that appeared in Time magazine in 2002.

That story didn’t go anywhere then. Maybe now the Clinton crew has more evidence — or maybe they just succeeded in peddling their story a second time.

Given these three different lights shining down on Clarke, on the Bush people and on the Clinton people, one might despair of ever learning the truth.

But happily, there’s a way to get the facts on the table; it’s called an investigation. Clarke is scheduled to testify, under oath, before the government’s commission investigating Sept. 11. And the Clinton people are similarly testifying. One assumes that the Bush people will also want to testify under oath — even the president himself. And there will be witnesses and corroborating evidence. That’s a good start toward getting the truth out. Because, as Martha Stewart has learned, lying to the feds is a serious matter.