"The government failed to protect the American people."

With those words, Tom Kean, the chairman of the National Commission on Terrorist Attacks Upon the United States, closed one chapter of our debate over Sept. 11 and opened a second.

The first stage was the fact-finding that this commission handled with exceptional skill under difficult circumstances and in the face of substantial resistance. Kean; his vice chairman, Lee Hamilton; and the commission's executive director, Philip Zelikow, were straightforward in interpreting their mission and creative in carrying it out.

By issuing clear and detailed interim staff reports, the commission gave citizens and policymakers alike precisely the information it was created to produce. And in making these reports public before producing its final document, the commission greatly reduced the chances that the conclusions it reached and the recommendations it made might be subject to closed-door manipulation.

The commission let its own example become what may be its most important recommendation. A lack of openness is a major problem for the Bush administration. Kean, Hamilton and their colleagues have shown that open government is the ally, not the enemy, of effectiveness. The process through which the commission's recommendations were produced guarantees that they will be taken seriously. And because the commission sought to balance the requirements of security with the demands of liberty, its proposals are less likely to add gasoline to Washington's inferno of partisanship.

But a fear of partisanship should not stop President Bush and Democratic candidate John Kerry from debating the commission's recommendations during the campaign. It's essential that they do so. In particular, the president should tell us why, 34 months after Sept. 11, he has not proposed some of these steps himself. One thing this report makes clear is that there is a lot left to do.

And that is why the second stage of the debate is about accountability, which cannot be dismissed as blame-mongering. Simply put, our government has a lot to answer for. Kean and the commission carefully avoided singling out individuals, but Kean's words yesterday were unequivocal: "This was a failure of policy, management, capability and above all a failure of imagination. . . . What we can say with a good deal of confidence is that none of the measures adopted by the United States government before 9/11 disturbed or even delayed the progress of the al Qaeda plot."

The report has critical things to say about both the Bush and Clinton administrations. But the attack happened on this president's watch, and Chapter 8, (titled after former CIA director George Tenet's evocative phrase) "The System Was Blinking Red," makes clear that the Bush administration had a lot of warning about the general threat, if not its particular locus. "There were more than 40 intelligence articles in the PDBs [President's Daily Brief] from January 20 to September 10, 2001, that related to Bin Ladin," the report says.

As for that famous Aug. 6 brief, "Bin Ladin Determined To Strike in US," the report offers what little it learned from Bush as to what he did with the information. "He did not recall discussing the August 6 report with the Attorney General or whether [national security adviser Condoleezza] Rice had done so," the report says. "He said that if his advisers had told him there was a cell in the United States, they would have moved to take care of it. That never happened."

The report said at another point: "No CSG [Counterterrorism Security Group] or other NSC [National Security Council] meeting was held to discuss the possible threat of a strike in the United States. . . . We have found no indication of any further discussion before September 11 among the President and his top advisers of the possibility of the threat of an al Qaeda attack in the United States."

There may be perfectly good explanations for this. The public should know what they are. A president asking for reelection on the basis of his handling of terrorism needs to explain far more clearly what he did with what he learned that summer. And, yes, Bill Clinton should do exactly the same thing concerning his decisions when he was president.

So let's be bipartisan: Clinton and Bush owe the nation back-to-back news conferences to react to the criticisms contained in the report. The news conferences should be open-ended. No plausible question should be left behind or evaded. If we want to move forward, we have to put the recrimination behind us. As the Sept. 11 commission has shown, openness and honesty are the best means to that end.