In my humble opinion.
If the US leaves, its because the risks outweigh the rewards.
The reward being, US political control of the region, and its resources.
Everyone is constantly going on about the troops, and the oil, but what about the corporations?
What about Haliburton(KBR) Bechtel Group, Fluor Corp. and Parsons Group.
The GOP didnt award them contracts in Iraq just to abandon them.
The US is never going to up and walk away, just leave every base they've built so it can be used by whomever has boltcutters. (or a b

mb)
The Corps will put plans to rebuild on hold, and focus on maintaining the Oil flow to the US and arms flow to whomever the US sees fit.
There will always be a military presence, at the very least to guard these Corporations so they can maintain said flow, and h

pefully rebuild everything 3 times.
Halliburton would NEVER move its headquarters to Dubai unless there was a guarantee that the US would for some reason or another remain strongly in the region.
http://www.marketwatch.com/news/sto...x?guid={71120983-5D06-416D-80D7-3B4348F8C514}
Not to mention Halliburton & KBR are the veins that keep our military forces alive.
Longterm, its in the best interest of the US Government and Multinational Corps for the US to stay in Iraq.
We simply need to be patient.
If and when the violence becomes too much of a risk, the US will retreat to bases, and escalate the training and arming the Sunni's.
Sunn's will probably be dubbed something fantastic, like "
Holy Warriors"
Iran will be coordinating training and funding and Shiite's.
All the while mumbling nuclear threats, which is ok, cause the US (No longer being spread out and tied down) will then have the availability of its full force to bring to bear if events call for it.
The little guys (Sunni's) will have all the help they need and more from the US, and if theyre lucky, some Sunni buds from Saudi Arabia.
This is all necessary in order to maintain the consistant and ideal levels of contained, controlled chaos, (CCC Im trademarking that.)and to maximize sectarian blood shed.
The US will just sit back, and watch while everyone explodes.
Sprinkling in some foregn aid, in the form of guns and rice.
The fight will rage on forever.
The US will stay a stones throw away in case there is a violent movement coordinated against Israel.
The US knows full well this occupation is a lost cause, and is doubly aware that it could in actuality go on forever.
So they take thier cues from the Afghanistan battle with Russia.
The warring factions in the region will
never stop fighting, and this is key.
As long as the US funds the minority in the battle, in world view, it is acceptable.
And any cost will gladly be looked upon as a future political investment in the region.
The Shiite wont win, the US wont allow it, they will pour arms into that region uintil its nothing but a crater so deep you can dig for oil with a spoon.
The US will (most likely) instigate violent attacks if there is a lull in the battle.
This is important to remember.
Thats why they are funding the Sunni's and not the Shiite.
Wearing down the powerful majority in the region is a solid tactic.
It wont end until events occur that call for the US to intervene, meaning the Sunni's gain the upper hand.
Giving the US political gains, because the future Sunni political representatives, will already be good buds with the US.
Once we finally establish political control of the region, all the Corporations can begin the very lucrative task of rebuilding.
I am not a doctor, but I play one, when im playing doctor.