I have a question:
1) Every surviving member of the Iraqi Army and Iraqi Police, many other government employees, members of many political parties (pro-US, pro-Western, pro-Democracy, whatever), and all of their families will flee the country. So will everyone who doesn't want to live under strict Sharia. Most of them will wish to resettle in the United States. This is based on our experience the last time we sold a US ally up the river, in 1975.
2) Al-Qaeda will take credit for throwing the United States out, and will be accorded the credit in the Arabic world. This results in huge amounts of new followers and new cash.
3) Saudi Arabia, Kuwait, the Gulf Emirates, all go under within a year or two. The pro-US faction will be terrified and unwilling to ask for US assistance (which we wouldn't be willing to give them), and the loony factions will be greatly emboldened. They will also have the resources of Iraq to draw upon. Now, instead of the Saudis trying to straddle the fence, we have the Saudis openly and publically sponsoring al-Qaeda. Without a focus on Iraq, al-Qaeda can resume planning and resourcing attacks on American assets worldwide and even in America.
4) Oil triples in price. At least.
5) Emboldened, Syria decides that the US cannot and will not support the Lebanese. Lots of dead Lebanese later, Lebanon is again a Syrian protectorate. Israel decides to conduct services on their nuclear weapons to make sure they are ready to go.
6) Iran does precisely as it pleases, knowing that the US isn't going to do a damn thing.
So on and so forth.
Anyone else seeing what I see?