Wars are all about one of three things:
1) natural resources (i.e. oil, any war over borders is based on natural resources)
2) suppressing some murdering villain bent on world domination (i.e. Hitler, Hussein, et al.)
3) religion (this one is more archaic, but if applied in the context political ideology it's still applicable, i.e. communism and the Vietnam and Cold Wars)
Which do you think is more justified? Iraq was a little of all three: 1) oil, 2,3) ruthless muslim dictator planning to use WMDs to kill everyone and take all of the ME oil (like he started to do with Kuwait)
If Obama had invaded Iraq the same idiots would be squawking about how it was our "moral duty" as part of our "social contract" with the world to save the civilians of Iraq from their murdering leader (i.e. what they did with Clinton in Serbia and what they're doing now with all those other shithole countries we're pissing money away in).
Hegemony!!!!