A large part of the problem was:
Defector 'Curveball' admits he lied about Iraqi WMD
By Douglas Stanglin,
USA TODAY Feb 15, 2011
An Iraqi defector code-named "Curveball," whose tales convinced the Bush administration that Iraq had secret biological weapons has admitted for the first time that he lied about his story, The Guardian reports.
Rafid Ahmed Alwan al-Janabi tells The Guardian in an exclusive interview that he made up the stories of mobile bio-weapons trucks and clandestine factories in an effort to bring down the Saddam Hussein regime.
The defector, who had fled Iraq in 1995, tells the British newspaper that he watched in shock as his claims were used to justify the war.
"Maybe I was right, maybe I was not right," he tells the newspaper. "They gave me this chance. I had the chance to fabricate something to topple the regime. I and my sons are proud of that, and we are proud that we were the reason to give Iraq the margin of democracy."
He claims officials implied that his cooperation would make it easier for his Moroccan-born wife and child to join him in Germany.
"Curveball" initially told his tales to the German secret service, and the information wound up in Secretary of State Colin Powell's speech in 2003 to the United Nations stating the case against Saddam Hussein.
"Curveball" tells The Guardian that when he complained to his German handlers that they had violated an agreement not to pass his information to a third country, he was told not to speak and was placed in lockdown for about 90 days.
http://content.usatoday.com/communities/ondeadline/post/2011/02/defector-curveball-admits-he-lied-about-iraqi-wmd/1