As I've said too often, the Iraq surge was explicitly proposed as a means to get Iraq's various factions to come together and build a common government and army and police force. From today's NYT:
Both the military and the police remain heavily politicized. The police and border officials, for example, are largely answerable to the Interior Ministry, which has been seen (often correctly) as a pawn of Shiite political movements. Members of the security forces are often loyal not to the state but to the person or political party that gave them their jobs.
The same is true of many parts of the Iraqi Army.
For example, the Fifth Iraqi Army Division, in Diyala Province northeast of Baghdad, has been under the sway of the Islamic Supreme Council of Iraq, the Shiite party that has the largest bloc in Parliament; the Eighth Division, in Diwaniya and Kut to the southeast of the capital, has answered largely to Dawa, the Shiite party of Prime Minister Nuri Kamal al-Maliki; the Fourth Division, in Salahuddin Province in northern Iraq, has been allied with one of the two major Kurdish parties, the Patriotic Union of Kurdistan.
More recently, the Iraqi Awakening Conference, a tribal-centric political party based in Anbar Province (where Sunni tribesmen, the so-called Sons of Iraq, turned against the insurgency during the surge) has gained influence over the Seventh Iraq Army Division, which was heavily involved in recruiting Sunnis to maintain security in 2006.
What if the real impact of the surge will be that it helped train and arm the various camps for an even more brutal civil war once the US has left? I guess that would be a nifty exit strategy and a way to save face. But it wasn't a success in the terms laid out by its own advocates. I hope it doesn't happen; but see few reassurances that it won't.