The public case that Iraq was pursuing nuclear weapons was built primarily on several suspicious items Iraq reportedly tried to import, such as uranium, aluminum tubes and precision machinery. But the uranium story is now in dispute, and many of the other items had possible uses unrelated to nuclear weapons.
Other information was either lacking, or suggested that no nuclear program was in the works, said the former intelligence officials, who analyzed Iraq's weapons during the run-up to the war. Some spoke on the condition of anonymity.
For example, "There was no solid evidence that indicated Iraq's top nuclear scientists were rejuvenating Iraq's nuclear weapons program," said Greg Thielmann, the former manager of the State Department office that tracked chemical, biological and nuclear weapons issues. Thielmann retired in September 2002.
Other former officials said the scientists weren't performing activities or going to places normally associated with work on a nuclear weapons program.
However, the U.S. National Intelligence Estimate on Iraq's weapons program said Iraq was trying to "re-establish and enhance its cadre of weapons personnel." The estimate was published in October.
The section of the classified document released Friday by the White House provided no details.
Before the war, U.N. nuclear inspectors at the International Atomic Energy Agency interviewed Iraq's nuclear scientists and found no indication that they were working on a weapons program.
"The whole thing was antiquated," said IAEA spokeswoman Melissa Fleming. "These guys were aging, they weren't working collectively and the facilities and infrastructure was dilapidated."
In its estimate, the CIA and military intelligence agencies concluded that Saddam was again trying to realize his long dream of becoming a nuclear power.
"Although we assess that Saddam does not yet have nuclear weapons or sufficient material to make any, he remains intent on acquiring them. Most agencies assess that Baghdad started reconstituting its nuclear program about the time that (U.N. weapons) inspectors departed — December 1998," says the estimate, a summary of intelligence analyses on Iraq's weapons programs that was assembled by the Central Intelligence Agency.
The estimate predicted, with "moderate confidence," that Saddam could build a nuclear weapon between 2007 and 2009.
The State Department's Bureau of Intelligence and Research dissented: "The activities we have detected do not, however, add up to a compelling case that Iraq is currently pursuing what (the bureau) would consider to be an integrated and comprehensive approach to acquire nuclear weapons."
White House officials said Friday that President Bush and his national security advisor, Condoleezza Rice, did not entirely read the report, the most authoritative prewar assessment of U.S. intellegence on Iraq, the Washington Post reports.
On Oct. 7, President Bush framed it this way: "Facing clear evidence of peril, we cannot wait for the final proof — the smoking gun — that could come in the form of a mushroom cloud." National security adviser Condoleezza Rice had used similar language Sept. 8, saying, "We don't want the smoking gun to be a mushroom cloud."
U.S. officials have announced no discovery in postwar Iraq that would validate that Iraq had revived its nuclear program.
Senior Iraqi nuclear scientists interviewed by The Associated Press in Baghdad said their efforts to build a weapon remained dismantled after the 1991 Gulf War. Shakher Hameed, a physicist who was one of Iraq's top nuclear officials in recent years, said there was no program.
"This whole American story of an Iraqi nuclear program is a lie," said Hameed, a frequent interviewee of both U.N. inspectors and U.S. intelligence officers. "The IAEA knew exactly what was going on here and they made it clear there was no program."
The suspected nuclear program in North Korea may show more compelling signs of having been revived: The North Koreans, unlike the Iraqis, claim they have a nuclear program. U.S. intelligence has learned of imports of materials useful in nuclear programs, tracked loading and offloading of trucks and other activity at known nuclear sites. U.S. and U.N. officials are now watching for signs that Pyongyang has begun reprocessing plutonium, a process that emits a kind of krypton that U.S. sensors can detect.
Saddam's well-established, pre-1991 pursuit of nuclear weapons led most intelligence analysts to assume he was still after them in recent years, said a defense official familiar with intelligence information. Reports of the Iraqis attempting to import suspicious items reinforced that thinking, the official said, on condition of anonymity.
A report that Iraq tried to import uranium from Africa was primarily based on documents, later determined to be forgeries, that alleged Iraq had sought uranium in Niger. President Bush's repetition of the allegation in his State of the Union address has led to a political firestorm, with critics accusing him of exaggerating intelligence to push for the U.S. invasion.
Other reports suggested Iraq was importing aluminum tubes for use in centrifuges to make weapons-grade uranium. While some CIA analysts believed the tubes were intended for centrifuges, experts with the Department of Energy and the United Nations concluded they were probably for conventional artillery rockets.
Other materials Iraq allegedly tried to import included magnets and precision machinery, which the United States said could be used in a nuclear weapons effort. But the IAEA noted that most of those items also have conventional industrial uses.
The U.S. intelligence estimate also notes "activities at several suspect nuclear sites." U.N. nuclear inspectors found no signs of new weapons programs at the scores of sites they checked out and neither did U.S. weapons hunters.
"We investigated every single intelligence claim that was provided alleging Iraq was pursuing nuclear weapons and did not find any evidence of the revival of a nuclear weapons program," the U.N.'s Fleming said.
Some kinds of uranium-enrichment programs require vast amounts of electricity; many need large, secure industrial sites, U.S. government scientists say. The soil around sites that are home to uranium weapons work also has greater traces of the substance than regular soil.
Andrew Wilkie, a senior Australian intelligence analyst who resigned in protest of his government's handling of prewar intelligence, said intelligence services did not pick up on telltale emissions and other signs that would point to a large-scale nuclear program.
"Every stage of the weapons cycle was missing," he said.