From the Summary: "Operation Iraqi Freedom overthrew Saddam Hussein's regime, but much of Iraq remains unstable because of Sunni Arab resentment and a related insurgency, compounded by Sunni-Shiite violence that a January 2007 national intelligence estimate (NIE) says has key elements of a 'civil war.' Mounting U.S. casualties and financial costs -- without clear improvements in levels of violence -- have intensified a debate within the United States over whether to wind down U.S. involvement without completely accomplishing initial U.S. goals. U.S. Defense Department reports, the December 6, 2006, report of the Iraq Study Group, and the NIE express pessimism about security in Iraq. President Bush addressed the nation on new initiatives in Iraq on January 10,2007 and announced a deployment of at least an additional 21,500 U.S. combat forces to help stabilize Baghdad and restive Anbar Province, as well as other measures to create jobs and promote political reconciliation. He and other officials have asserted that the new security plan would build on important successes: two elections (January and December 2005) that chose an interim and then a full-term parliament and government; a referendum that adopted a permanent constitution (October 15, 2005); progress in building Iraq's security forces; and economic growth. While continuing to build, equip, and train Iraqi security units, the Administration has worked to include more Sunni Arabs in the power structure, particularly the security institutions. Some U.S. officials say the 2007 Baghdad security plan is producing at least some reduction of sectarian violence and allowing for an increase in commerce and ease of movement around Baghdad."
CRS Report for Congress, RL31339