WHO KNEW WHAT WHEN

For all the charges of deception against the Bush administration over the war, the one easiest to check has been the repeated White House statement that Democratic critics saw the same intelligence as the administration before the fighting began. White House and Pentagon officials repeatedly made flat statements about the Iraqi threat without disclosing private doubts about the credibility of sources and documents.

Some examples:

. The aluminum tubes sought by Saddam Hussein. On Sept. 8, 2002, The New York Times reported leaked information that Saddam Hussein had tried to acquire aluminum tubes “specifically designed” for a nuclear weapons program. Starting that same day, Vice President Cheney, President Bush, Colin Powell, Condoleezza Rice and the State Department’s spokesman all cited the tubes as proof that Saddam was trying to start up his nuclear weapons program.

Congress and the public learned only in July 2003, four months after the invasion began, about detailed reservations by the Energy Department and the State Department’s intelligence bureau. They concluded that the tubes were unsuited for nuclear weapons work and most likely were for rockets. This was in an appendix to the publication of an edited version of the top-secret October 2002 National Intelligence Estimate.

. Niger’s yellowcake. An Italian intelligence report that Saddam had been trying to buy this form of uranium found its way into the British and U.S. intelligence systems. But insiders knew that the Italians and the British and the U.S. Central Intelligence Agency all judged the report questionable. Documents supposed to prove the matter turned out to be forgeries. Yet Mr. Cheney, Mr. Powell, Ms. Rice and the president himself, in his 2003 State of the Union address, made the same charge despite objections by the CIA.

? The “mushroom cloud.” President Bush and Ms. Rice raised the specter of nuclear war with repeated warnings of a “mushroom cloud” while concealing the fact that the State Department’s Bureau of Intelligence and Research had raised serious doubts that Saddam had revived his nuclear weapons program. The bureau’s reservations were not made public until July 2003, long after the invasion was launched.

Why was the prewar intelligence so skewed? We will know more when and if the Republican-controlled Senate Intelligence Committee completes part two of its report on pre-war intelligence. Part one was harshly critical of the CIA’s performance. Yet to come is a report on how the Bush administration used intelligence in the buildup to the war.

We already know, however, that much of the prewar intelligence came from a highly questionable source, Ahmad Chalabi. This Iraqi ?migr? was once a favorite of Mr. Cheney and the Pentagon, then was discredited and now is a rising star in the new Iraqi government. He persuaded some officials that Saddam had vast stores of nuclear and biological weapons, that Saddam and al-Qaida were in cahoots, and that the Iraqi people would welcome the American invaders.

Such false and misleading information made its way to the president and vice president via the “smokestack” route. That is, raw intelligence reports, with the help of a special intelligence division in the Pentagon, bypassed the usual “vetting” process, in which skilled operatives assess the background and credibility of sources.

The Senate Intelligence Committee has a rich field of investigation for part two of its report.