For instance, Bush claimed in his Jan. 28, 2003, State of the Union address that Saddam was working to obtain "significant quantities" of uranium from Africa, a conclusion the president attributed to British intelligence and made a key part of his assertion that Iraq had an active nuclear weapons program.
More than a year later, the White House retracted the statement after questions were raised about its veracity.
But the Senate report makes it clear that even in January 2003, just before the president's speech, analysts at the CIA's Weapons Intelligence, Nonproliferation and Arms Control Center were investigating the reliability of the uranium information.
Similarly, the president's intelligence commission, chaired by former appellate judge Laurence Silberman and former senator Charles Robb, D-Va., disclosed that senior intelligence officials had serious questions about "Curveball," the code name for an Iraqi informant who provided the key information on Saddam's alleged mobile biological facilities.
The CIA clandestine service's European division chief had met in 2002 with a German intelligence officer whose service was handling Curveball.
The German said his service "was not sure whether Curveball was actually telling the truth," according to the commission report.
When it appeared that Curveball's material would appear in Bush's State of the Union speech, the CIA Berlin station chief was asked to get the Germans to allow him to question Curveball directly.
On the day before the president's speech, the Berlin station chief raised a warning about using Curveball's information on the mobile biological units in Bush's speech.
The station chief warned that the German intelligence service considered Curveball "problematical" and said their officers had been unable to confirm his information.
The station chief recommended that CIA headquarters give "serious consideration" before using that unverified information, according to the commission report.
Nonetheless, Bush told the world the next day, "We know that Iraq, in the late 1990s, had several mobile weapons labs ... designed to produce germ warfare agents and can be moved from place to a place to evade inspectors."
He attributed that information to "three Iraqi defectors."
A week later, Powell said in an address to the United Nations that the information on mobile labs came from four defectors, and he described one as "an eyewitness ... who supervised one of these facilities" and was at the site when an accident killed 12 technicians.
Within a year, doubts emerged about the truthfulness of all four, and the "eyewitness" turned out to be Curveball, the informant the CIA station chief had red-flagged as unreliable. Curveball was subsequently determined to be a fabricator who had been fired from the Iraqi facility years before the alleged accident, according to the commission and Senate reports.