Leaders like Saddam Hussein and others throughout the region who help put in place and expedite terrorist growth cells will reconsider knowing it's their own head that will dangle in the hangman's noose.
Now you can argue that the moral-tonal ramifications of the war are reprehensible and the whole thing is a philosophical fallacy (Jon Stewart, Stephen Colbert), but the bottom line is that going over there and kicking every ass we can find is the best way to deter future attacks. (Why aren't we attacking Saudi Arabia then? I don't know but I can only imagine that would fulfill any and all doomsday prophecies foretold in almost every major religious text.)
ENOUGH-WAS-ENOUGH about 20 years ago. The perpetrators of 9-11 knew full well that the breadth of the U.S army would befall them as was to their design.
But I'm willing to concede the middle and agree that our policy will either reflect the one I painted above or we pull everyone everywhere back home and go back to Isolationist America. But then which is it?? I don't think there's much middle ground there anymore.