According to this CFR backgrounder, neighboring Arab states are increasing their aid to and engagement with Iraq as a pre-emptive security investment in the event of an increasingly expected American troop withdrawal. Of course, forcing Iraq’s neighbors to assume more of a burden in stabilizing the country was one of the logical underpinnings of a withdrawal timeline, along with the pressure it would place on the Iraqi political process to make progress on power sharing arrangements. So, basically, two for two.
Meanwhile, why does nobody ever mention the November 2006 midterm elections, which conclusively demonstrated that American public opinion had turned against the war, as a contributing factor to the reduction in violence in Iraq? If you take a look at this graphic from the Economist (via The Global Buzz), the peak in Iraqi civilian casualties actually corresponds to the end of 2006, before the announcement and deployment of the Surge. (I imagine the spike in American military casualties in Summer 2007 is due to the increased deployment and forward engagement of American forces in Baghdad.)
Contrary to the worst case scenarios conjured up of bloody internecine fighting, the possibility that American forces might soon be leaving Iraq seems to have a way of focusing people’s attention on pulling back from the brink and finding ways to make sure things don’t fall completely apart. In other words, pretty much what advocates of disengagement suggested, across the board.