Yet the administration has no evidence that Iraq is cooperating with al Qaeda or is likely to do so. Wrong, as outlined in the President's Cincinnati speech, and in numerous published stories, most notably a long investigative piece in the New Yorker.
The most important reason to attack Iraq is that Iraq is the nail sticking up, and the nail sticking up gets hit. That sounds facetious, but it's not. The best way to combat terrorism comprehensively is to rearrange the politics of the entire Middle East, and deposing Saddam is an excellent place to start.
With the first bombing runs, Saddam will shoot one of his doubles in the head and have one of his aides run the poor bastard out to the cameras for the world to see ... 'We've killed him so you can stop now.' And the despotic democrats and their postponeNIKS will cry 'peace' and 'safety' and Saddam will continue to be a thorn or nail as you put it. If there be war, crush the enemy and disarm the survivors!