The entire concept of the surge/escalation is to create a temporary increase in American troops to clear significant areas of major cities and supply systems of active insurgents, and then to hold onto these areas with a combination of Iraqi and American forces.
This is a limited mission because of doctrinally insufficient manpower availability. To secure just Baghdad requires, according to the Petreaus docrtine, between 150,000 to 180,000 motivated, and loyal counterinsurgents. To secure the entire Sunni Arab population outside of Baghdad requires another group of the same size, and to secure the Shi'ite Arab population outside of Baghdad means doctrinally another 400,000 loyal counterinsurgents. Not going to happen.
The band and raid strategy is an economy of force mission with the Iraqi Army expected to fill the vast majority of the post-sweep infantry roles. But there is a problem here, as reported by the AP:
There also are signs of an unwillingness by Iraq’s leadership to commit forces to operations outside Baghdad. About 11,000 Iraqi soldiers were assigned to a U.S.-led offensive launched last month in and around Baqouba, on Baghdad’s northeastern rim. Only about 1,500 showed up, U.S. officials said......
The region of Salman Pak, about 15 miles south of Baghdad, has seen a spike in activity by Sunni insurgents since a U.S.-Iraqi security push began in the capital nearly six months ago, said Col. Wayne Grigsby Jr., commander of the Army’s 3rd Brigade, 3rd Infantry Division.....
Since his arrival here in March, Grigsby said he put in several requests for two Iraqi army battalions - up to about 1,500 men - to join the 3,800 U.S. troops now in the area. He is still waiting.
This is a common occurrence. The Iraqi Army and its political masters routinely do not see themselves as a critical component and beneficiary of the American operational plans, so they don't show up. And in an operational plan where the Iraqi Army is needed to show up to produce the possibility of positive and sustained results, that is a slight and recurring problem.