It sounds so simple. Troops go to Iraq, troops leave Iraq. But it isn't. First of all, because not all soldiers are the same--some are combat troops, and some are non-combat troops and these categories are addressed differently in withdrawal plans. Those in combat perform offensive operations. Non-combat troops may provide training and mentoring, assist Iraqi troops, conduct intelligence and communications functions, among other tasks. Second, because even definitive agreements are open to negotiation, even the recently signed Status of Forces agreement, which sounds definitive. And last, because the American leadership in Iraq maintains that it will negotiate or potentially override agreements if they perceive the need. Here's where things stand on all that:
Number of troops currently in Iraq: About 149,000.
Obama's campaign pledge on a timeline: All combat troops out by the summer of 2010. The forces remaining would train Iraqi forces and otherwise perform support for counterterrorism or counterinsurgency. Obama has already suggested he may show some flexibility.
Status of Forces Agreement (SOFA) signed between Iraq and the United States in November 2008 : Says that the United States must have all combat tropps out of towns and cities by July 2009, and withdrawal of all troops, combat and non-combat forces, by the end of December 2011.
Iraqi opinion on Troop Withdrawal Divided. Iraq will hold a referendum on the Status of Forces Agreement in July 2009 and may vote for the removal of all troops by the summer of 2010.
American commanders, December 2008: General Ray Odierno, the highest commander in Iraq and CENTCOM Commander David Petraeus have designed a plan that will have 7,000-8,000 combat troops out by the summer of 2009, with the removal of all combat troops after May 2010.
Commentators note that this plan would take longer than Obama's campaign (which was already made obsolete by the SOF Agreement) and that there is a substantial discrepancy between the removal of all troops, as demanded by the SOFA, and the removal of combat troops only.
The New York Times notes that the plan may seek to meet Obama's plan by "remissioning" combat troops as non-combat forces and, moreover, that some may continue to conduct patrols with Iraqi forces, which is essentially a combat function.
Number of troops who will remain in Iraq following the official withdrawal of troops: Estimates currently range from 30,000 to 70,000. Secretary of Defense Robert Gates said that "several tens of thousands" may remain on the Charlie Rose show on December 17.