For starters, the two captured planners of the 9/11 attacks, Binalshibh and Khalid Sheikh Mohammed, have both reportedly denied Iraqi involvement during interrogations. Next, those who argue for Iraq's guilt rely on dubious claims. The first is an on-again, off-again Czech assertion that Mohamed Atta met with an Iraqi agent in Prague. But American intelligence agencies now believe the meeting did not occur. Several conservative analysts—notably Laurie Mylroie and former CIA Director James Woolsey—have pushed the idea that the first World Trade Center bombing was an Iraqi intelligence operation, and thus Sept. 11 might have been too. They believe that Ramzi Yousef, the architect of the first bombing, was acting for the Iraqis, and since Yousef's uncle is Khalid Sheikh Mohammed, Iraq should be suspect again. But no one has managed to show that Iraq sponsored Ramzi Yousef or the 9/11 terrorists.

Perhaps the most compelling evidence against Iraqi involvement is that the Bush administration hasn't made a case for it. The president is desperate to link Iraq to al-Qaida. But so far, his team hasn't managed to find anything tangible that connects the Hussein regime to Osama Bin Laden (much less to 9/11). The administration wants the nefarious alliance so much that if it had any evidence, it surely would have leaked it. This does not prove, however, that Iraq and al-Qaida never cooperated. The polls, in fact, may reflect a kind of commonsense logic: Saddam Hussein and al-Qaida share a pathological hatred of the United States, so it's entirely possible that they collaborated, even if we don't know how.