The Obama Administration is facing a security environment in Iraq vastly improved over that which prevailed during 2005-2007, although still not completely peaceful or without potential to deteriorate significantly. Some U.S. officials believe that further U.S. military presence might be needed beyond the projected 2011 withdrawal date, and that political disputes among Iraqi factions could escalate and reignite civil conflict in the absence of a U.S. presence. This report discusses these issues in detail, as well as the factors that have contributed to the planned withdrawal of U.S. troops, including mounting casualties and financial costs.