Intelligence: Powell�s Case, a Year Later: Gaps in Picture of Iraq Arms: "After several lengthy sessions, he appeared in New York on Feb. 5, with Mr. Tenet, the director of central intelligence, seated behind him, to tell the United Nations Security Council that the evidence added up to 'facts' and 'not assertions' that Iraq had large stockpiles of chemical and biological weapons and that it was reconstituting its nuclear weapons program and building a fleet of advanced missiles.
Mr. Powell's testimony, delivered at a moment of high suspense as American forces gathered in the Persian Gulf region, was widely seen as the most powerful and persuasive presentation of the Bush administration's case that Iraq was bristling with horrific weapons. His reputation for caution and care gave it added credibility.
A year later, some of the statements made by Mr. Powell have been confirmed, but many of his gravest findings have been upended by David A. Kay, who until Jan. 23 was Washington's chief weapons inspector.
Doubts had surrounded much of the evidence ever since American inspectors arrived in Iraq. Yet in the days since Dr. Kay definitively declared that Iraq had no significant stockpiles of chemical or biological weapons when the invasion began in March, Washington has been seized by the question of how and why such an intelligence gap happened.
Even some Republican lawmakers are talking about a failure of egregious proportions � akin, some think, to the failure to grasp the forces pulling apart the Soviet Union in the late 1980's. President Bush is considering whether to order an investigation into the intelligence failure, an action he has so far resisted.
Some answers can be found in a dissection of the case that Mr. Powell presented, and an examination of some of the underlying intelligence information"

Our conservative estimate," Mr. Powell declared in his United Nations presentation, is that "Iraq today has a stockpile of between 100 and 500 tons of chemical weapons agent" or enough, as he put it, "to fill 16,000 battlefield rockets."

To make that case, Mr. Powell unveiled before the Security Council an array of previously classified evidence on a scale not seen in that room since Adlai Stevenson appeared during the Cuban missile crisis in 1962, armed with photographs of Soviet missiles. ("This was my Adlai moment," Mr. Powell joked later.) But in retrospect, the satellite photographs and tape-recordings of intercepted communications that Mr. Powell played that day now seem to describe actions that are less fearsome than they first appeared.

Nearly all evidence revolved around what Mr. Powell described as suspicious activities at sites Iraq had used before the Persian Gulf war of 1991 to manufacture chemical weapons. There was little question that huge amounts of Iraqi chemical weapons remained unaccounted for — the United Nations inspectors listed their whereabouts as a mystery in a final report after leaving Iraq in 1998 — and the prospect that those chemicals could be unleashed was a major concern as the Pentagon made final plans for war.

Among the intercepts that Mr. Powell replayed were some from November 2002 and January 2003, in which voices identified as those of Iraqi officers expressed concern at the possible discovery by United Nations inspectors of a "modified vehicle" and "forbidden ammo."

But as senior intelligence officials acknowledged in October 2003, during an interview at the C.I.A.'s headquarters, the actual evidence that Iraq had resumed production of chemical weapons was limited. They said their prewar conclusion — that Iraq still possessed the chemicals — had been based on more than just the satellite photos of "decontamination vehicles" and tarp-covered trucks covered at the facilities. It also relied, they said, on human intelligence reports of what one called "abnormal activities" beginning in March 2002 at former chemical weapons sites.

They acknowledged that some American intelligence agencies had resisted the conclusion and had voiced "very legitimate objections," including the possibility that the suspicious movements involved something far more benign: commercial chlorine-manufacturing activity.

But a National Intelligence Estimate in October 2002 had asserted with "high confidence" that the activity indicated that Iraq's chemical weapons program was once again alive. Later, from December 2002 to February 2003, the official said, "we began to see those materials, whatever they were, showing up in what we call a field ammunition storage area" as Iraq prepared "for the potentiality of war."