By late 2006, 31/2 years after the dramatic capture of Baghdad by U.S. and coalition forces, the war in Iraq was going badly. Sectarian tensions had erupted into violence and American public support for the war was at an all-time low. For better or worse, the George W. Bush administration decided to gamble on a troop increase, sending thirty thousand additional U.S. troops to Iraq in order to stop the bloodshed and bring stability to Baghdad and the surrounding area. By June 2007, they were all in place, and the so-called surge began. "Surging South of Baghdad" covers this crucial period in the Iraq war from the perspective of a single division operating in the region south of the Iraqi capital. Before the surge, this slice of territory between the Tigris and Euphrates Rivers had become an insurgent safe haven where the enemy cached weapons and built bombs that fueled sectarian violence in Baghdad. Placing the 3d Infantry Division there bolstered a flagging coalition presence in the area and began the process of stabilization and rebuilding. This account offers a snapshot of the surge, its successes and shortcomings, and shows how the Army coped with the changing demands of the modern combat environment. Although organized and trained as a heavy conventional unit, the 3d Infantry Division readily adapted to its mission south of Baghdad, combining firepower and maneuver with civic action and economic rejuvenation. The story of its deployment during 2007 and 2008 is one of fierce combat and insidious roadside bombs as well as mediating between feuding sectarian groups and performing humanitarian missions. Counterinsurgency in the twenty-first century demands this seemingly contradictory combination.