Future Prospects for Iraq
That's where it looks like were headed...
So best case scenario, you have a cold-war detente between Iraq's three main factions, a restless Turkey, a restless Iran, and a restless US occupation, all bundled up in a low-intensity insurgency in the mold of Northern Ireland. (Back in the rose petal days, the neocons were dreaming of an Israel-friendly Chalabi-led Iraqi regime.)
Mid-case scenario, we have a Middle Eastern Colombia -- a semi-functioning Democracy under siege from a whole host of paramilitary groups. Lots of assasinations, lots of territory outside effective government control, and a government held hostage to the forces of violence.
Worst case, more of the same. 100+ US and allied dead per month (which, incidentally, is approaching the level of casualties suffered by the Soviets during their Afghanistan invasion and occupation). A failed state, breeding ground of future terrorists, and a crucial region destabalized by endless war and religious fanaticism.