Marc Lynch and John Nagl argue that we need to amp up our diplomatic efforts in Iraq:
America's contribution to dealing with these continuing problems [in Iraq] will be primarily political and diplomatic, not military. A commitment to drawing down military forces should not mean political disengagement. Iraq is as important to the interests of Iran, Turkey, Syria, Saudi Arabia and other regional players as it is to those of the US. Undoubtedly, those countries will continue to be deeply involved in Iraq whether or not Americans stay on the field.
Lynch goes into more detail at his blog.