Richard Clarke and others say that the Bushies, entering office amid warnings about al-Qaeda, were fixated on Iraq. Clarke says that the fixation remained even after 9/11. Why would that have been the case? Tony Karon of Time magazine may have answered this question last summer:
One reason so many hawks seemed ready to make the case for retaliating against Saddam as well as bin Laden may have been the influence of Laurie Mylroie, a conservative scholar who had convinced herself and a number of influential conservatives, although not the U.S. intelligence community, that Iraq had been behind the 1993 World Trade Center bombing, and was very likely behind 9/11, too. But as eccentric as her argument was to the U.S. intelligence community, it was hailed by Wolfowitz, who wrote in a blurb to her book that it "argues powerfully that the mastermind of the 1993 World Trade Center bombing was actually an agent of Iraqi intelligence." And invade-Iraq cheerleader Richard Perle, formerly head of Rumsfeld's Defense Policy Board, wrote in his own blurb: "Laurie Myroie has amassed convincing evidence of Saddam Hussein's involvement in the first attempt to blow up the World Trade Center. If she is right, and there are simple ways to test her hypothesis, we would be justified in concluding that Saddam was probably involved in the September 11, 2001, attacks as well."
Digby at Hullaballoo quotes that here, and has a lot more to say about Mylroie, as does Matthew Yglesias at The American Prospect. Oh, and while you're at it, you might want to read Peter Bergen's Washington Monthly profile of Mylroie.
I invoke Ms. M. on a regular basis, but the influence of her ideas still isn't widely recognized. It might be an oversimplification to say that Mylroism made 9/11 possible. Then again, it might be pretty close to the truth.