Hortlund, this may surprise you but, you are correct. However there is even more to lose by going in without due caution.
#1 priority: War against terrorism
By Unilaterally going in on Saddam you will weaken that #1 objective.
Terrorism is not a State, it is a shadowy entity with no borders. By acting rashly, 1000's more of these shadowy figures will emerge due to an act of aggression.
And please note that I said DUE CAUTION.