Politics is all about maintaining a very delicate balance of interests and this is what you must keep in mind. Do you really believe that the U.S are about to throw Saddam out of Iraq just because he's an insane dictator or because he carries nukes and chemical weapons? I don't think so. If that were the case, then why did they support him in the 80s against Iran and Homeini?
Pinochet was a dictator too in Chile but then again the US didn't seem to bother when he squashed his political opponents like bugs and commited his own share of crimes against humanity. As a matter of fact, it was the US who brought him in power and helped him assasinate Alliente.
There are plenty of examples like the above that can prove you wrong in case you believe in this "fight against terror" utopia. What I'm trying to say is that you all should look a bit deeper. What does Iraq have that would be of interest to the mighty U.S.A? Yep, you've guessed right:
Oil. Who's standing in their way? Saddam Husein. What do we do? Wipe him out of the face of the planet. That simple.
Saddam Husein is a lunatic and a fanatic, no question about that. After all, he always was (even when he enjoyed full US support).
O tempora, O mores.