I think the real question is what has Saddam done since 1991 and why does that justify unleashing one of man's most destructive and terrible things being war in a region that is itself divided about the action. Unpopular and expensive.
We have know Saddam was an evil dictator for a long time, if we didn't need to attack since 1991, then we don't need to now as far as that argument goes.
I could argue against the war all-night but I'd rather play some vidoegames!