Only U.S. Can Stop Iraq Civil War

Most Americans seem ready to consign the Iraq war to history. They've watched tank convoys leave Baghdad, and they've heard the president underscore his campaign promise to draw down U.S. forces, leaving roughly 50,000 in the country as of Aug. 31. Moreover, Iraq and the U.S. have agreed that the remaining U.S. troops will be gone by December 2011. But history suggests that unless the U.S. is willing and able to remain committed to Iraq's security and prosperity — and Iraqis know it — the country is at risk of spiraling back into civil war.

Civil conflicts like those we have seen in Iraq since the U.S.-led invasion often recur when parties to a conflict fail to dedicate themselves to a peace process. Scholars call this the "commitment problem." If a state is without effective political institutions or professional armed forces, and if no warring faction has been able to achieve a decisive military victory, only an impartial outside power can enforce the belligerents' demobilization and political power-sharing to prevent conflict from flaring up again.