Here’s a good op-ed from Najim al-Jabouri, the former mayor of Tal Afar, that goes into some detail about the pervasive and persistent sectarianism within the Iraqi security forces. These paragraph, for instance, crystallize the problem in alarming ways:

[T]he 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.

I wish I had known this before hearing from Maliki aides who minimize the extent of sectarianism or treat it as last year’s problem. Jabouri thinks it’s time to purge the Defense and Interior ministries of high-level sectarian figures and shuffle the security services to break up these blocs.