Cause iraq tried to kill bush's daddy.
I used to believe the same but the Bush Sr. attack in Kuwait was never linked to Saddum.
Here are the reasons I feel Bush Jr. is doing it:
1) Oil for personal profit.
2) Oil for special interests.
3) Revenge against Saddum for first being a good puppet but later becoming an Evildoing independent.
4) To send a strong message to all Evildoers (Arab states, N. Korea, China).
5) Phase one of targeting governments the Bush folk want eliminatated.
6) Gain another foothold in the region to get modern day American Empire expansion off to a great start.
7) National security/defense of Israel.
8) Oil for nation's future energy needs/to prevent another oil shortage like we had in the 70's.
9) To support the U.S. military-industrial complex (e.g. Westinghouse, McDonald Douglass/Boeing/Lockheed, G.E.).
10) Possibly to give a small boost to a segment of our economy.
11) To piss off Moonbeam.