Here’s an excellent article called “The First Casualty” in The New Republic. It details how the Bush Administration shaped, shaded, influenced and tainted the intelligence community’s data and analysis on Iraq in order to justify a war. A few snippets:

“Yet there was no consensus within the American intelligence community that Saddam represented such a grave and imminent threat. Rather, interviews with current and former intelligence officials and other experts reveal that the Bush administration culled from U.S. intelligence those assessments that supported its position and omitted those that did not. The administration ignored, and even suppressed, disagreement within the intelligence agencies and pressured the CIA to reaffirm its preferred version of the Iraqi threat. Similarly, it stonewalled, and sought to discredit, international weapons inspectors when their findings threatened to undermine the case for war. …

“Had the administration accurately depicted the consensus within the intelligence community in 2002–that Iraq’s ties with Al Qaeda were inconsequential; that its nuclear weapons program was minimal at best; and that its chemical and biological weapons programs, which had yielded significant stocks of dangerous weapons in the past, may or may not have been ongoing–it would have had a very difficult time convincing Congress and the American public to support a war to disarm Saddam. But the Bush administration painted a very different, and far more frightening, picture.”