Mass hysteria at the political level. Iraq has been our whipping boy for over a decade, the perfect foil to move headlines for presidents, senators, representatives, and others worldwide. Problem was, they got caught up in their own whirlwind and actually believed it - say something long enough and it becomes true. A more discerning leader not surrounded by drum-beaters would have ignored the noise and focused on the problem. Bush is not a discerning leader; never was.
Given that Hussein engaged in repeated acts of war against us after 9/11, I take that you think we should have ignored his attacks on our military.