U.S. intelligence about Hussein's military also was wrong. Although Pentagon officials warned at the outset of the war that Iraq's army would use chemical weapons if U.S. forces crossed a "red line" around Baghdad, Duelfer said no such plan was found to exist.
Duelfer's report also challenged or downplayed previous claims -- by Kay and Duelfer -- that suggested Hussein had a secret weapons program underway.
In Senate testimony in March after he took over the survey group, for example, Duelfer said that a series of small biological laboratories run by the Mukhabarat, Iraq's security service, could have been used to produce bio-warfare agents.
But the official who briefed reporters said that further investigation showed the labs were not for military purposes.
"It appears they were producing small amounts of poison, but they were not for military weapons," the official said. He said it appeared that the labs were designed to produce toxins such as ricin to use in assassinations, not as weapons of mass destruction.
Duelfer also rejected administration claims that two truck trailers seized in Iraq after the war were designed to produce germ weapons. This year, Vice President Dick Cheney described the trucks as "conclusive" proof of Iraq's illicit weapons.
"Those are clearly, in my judgment, for the production of hydrogen," Duelfer said. "They have nothing to do with biological weapons." The intelligence on the mobile facilities was mostly from an Iraqi defector code-named "Curveball" who had "turned out to be largely a fabricator," Duelfer said.
Duelfer will return to Baghdad and the Iraq Survey Group will continue investigating several unresolved issues, he said, including study of a "new influx" of millions of pages of documents. The survey group has more than 700 Arabic translators examining the material at a military base in Qatar.
But Duelfer said he believed there was a "less than 5% chance" that a weapons stockpile would be found or that the picture of the prewar arms program would change significantly. Duelfer did not say how long he expected the search team to remain active, but said the remaining work "is a much diminished task and requirement."
After interrogating Hussein and several of his top lieutenants, Duelfer concluded that some of Hussein's decisions about weapons programs were never put on paper, or even clearly stated.
