Iraq's potential nuclear threat has been at the center of the controversy over whether the intelligence used to justify the war was accurate, and portrayed accurately. No weapons have been found in four months since Baghdad fell.
Last month, the White House retracted one claim it had made against Saddam Hussein: that his government sought uranium in Africa. The claim, leveled in the president's State of the Union speech, referred to British evidence of a suspected deal in Niger.
Documents supporting the allegation were later proven false by the International Atomic Energy Agency.
The White House has depicted the Niger claim as a 16-word gaffe resulting from botched communications between the CIA and the National Security Council.
But administration figures made no less than six references to the same allegation in the days around the State of the Union.
And that came after a U.S. envoy largely dismissed the claims in early 2002. The CIA asked the British to omit the claim in September, and later kept a reference to the claim out of an October speech by the president.
The Washington Post says administration figures pushed other shaky allegations, withheld contrary evidence and rarely corrected misstatements.
For example, President Bush often referred to meetings between Saddam and his nuclear advisers, without noting that the top three nuclear experts in Iraq had non-weapons roles: one ran a copper factory, another a graphite plant and a third an engineering design center.
U.S. reports referred to Iraq building new facilities on former nuclear sites, but didn't know what the buildings were for. In February, U.S. experts in Iraq confirmed nothing illegal was going on at the sites.
Officials, including Vice President Dick Cheney, often referred to evidence from a key Iraqi defector, Hussein Kamel, in claiming Iraq was still pursuing nukes. But Kamel had told debriefers Iraq's program was active before the Gulf War, and not when he defected in 1995. Kamel was killed on his return to Iraq in 1996.
The White House also continued to push the theory that Iraq was importing aluminum tubes for enriching uranium to weapons grade, even though, according to The Post, experts told the government for more than a year that the tubes were not suited for that purpose. And there was evidence the tubes were perfectly suited for Iraq's stated purpose — to build rockets.
The IAEA also refuted the White House theory about the tubes.
Referring to a type of uranium Iraq was thought to possess, a senior policymaker told The Post "You can stare at the yellowcake (uranium ore) all you want. You need to convert it to gas and enrich it. That does not constitute an imminent threat, and the people who were saying that, I think, did not fully appreciate the difficulties and effort involved in producing the nuclear material and the physics package."
Doubts about the nuclear claims were reported in the National Intelligence Estimate completed in October. The State Department's intelligence arm was not convinced Iraq was actively restarting its program. Both State and the Department of Energy doubted the theory that the aluminum tubes had a weapons purpose.
CIA director George Tenet, in a lengthy statement published by The Post, defended the NIE and the administration's claims.
"Our judgments have been consistent on this subject because the evidence has repeatedly pointed to continued Iraqi pursuit of WMD and effort to conceal that pursuit," Tenet wrote.
He added that the allegations about uranium deals and aluminum tubes were not included as among the key findings in the NIE.
Committees in both houses of Congress are probing the prewar claims, as is an internal review by the CIA.
Before the war the administration claimed Iraq possessed chemical and biological weapons. As weeks have passed without any finds, officials are instead pointing to a belief that Iraq ran weapons "programs."
However, confidence seems to have grown that new evidence will soon emerge.
CIA adviser David Kay, who is serving as a special adviser for the weapons search, told lawmakers last month that inspectors have found physical evidence of Iraqi activity on weapons of mass destruction.
Without offering any detail, he said investigators had made a "tactical and strategic decision" to focus on biological rather than on chemical or nuclear programs.
Agene France-Presse reports the British government plans to release a new report on evidence that Iraq has produced biological weapons.
But The New York Times reports Defense Intelligence Agency experts now think two trailers found in northern Iraq are not mobile biological weapons factories, as the White House claimed, but machines for producing hydrogen, as Iraq claimed.
State Department experts previously reached a similar conclusion. The CIA and DIA, however, stand by the earlier conclusion that the trailers were likely mobile bioweapons factories.
Meanwhile, a judicial inquiry into the death of a British weapons expert was under way Monday.
CBS News Correspondent Steve Holt says the official purpose of the hearing is to investigate David Kelly's apparent suicide. But the heart of the matter is the allegation that the Blair government hyped up its evidence about Saddam's forbidden weapons.
Shortly after Kelly was revealed to have expressed doubts about some of that evidence, in off-the-record briefings for reporters, he was found dead.
The list of witnesses goes all the way up to Prime Minister Tony Blair himself, who is under increasing pressure to justify his handling of the Kelly affair and his arguments in favor of war in Iraq.