Oh, that’s an easy one to answer.
The rhetorical question at the end of this post is "What is the United States doing in Iraq’s civil war?" The answer, of course, is "making friends and relations of the B*sh junta very very wealthy."
After all, what's a little Rwandan-class slaughter of civilians compared to the opportunity of being able to keep taking wheelbarrels of cash out of the US treasury? After all, any president can drive the United States into an unwinnable war that kills countless civilians, but the opportunity to use a slowly and carefully installed Soviet-style dictatorship to extract money beyond the dreams of avarice from the coffers of a superpower almost never comes along, and someone else already did the drive-through looting of the USSR's treasury, and if you're an evil sociopath it would be an offense before G-d to not take advantage of that opportunity.
Maximum Leader Genius, on the other hand, wouldn't even know where to find Iraq on a map. All he cares about is being able to have people tortured to death at his command, and he's already got 35000 or so victims tucked away in his little gulag.