In this Thursday, Nov. 15, 2012 photo, a U.S. Marine, left, looks down a hole in a tunnel used in the construction of the Kajaki dam in Helmand province, south of Kabul, Afghanistan. A

 

              In this Thursday, Nov. 15, 2012 photo, a U.S. Marine, left, looks down a hole in a tunnel used in the construction of the Kajaki dam in Helmand province, south of Kabul, Afghanistan. A
In this Thursday, Nov. 15, 2012 photo, a U.S. Marine, left, looks down a hole in a tunnel used in the construction of the Kajaki dam in Helmand province, south of Kabul, Afghanistan. A $500 million effort to refurbish the massive dam and hydro-electric power system with an extensive network of power lines and transmission substations is supposed to bring electricity to 332,000 people in southern Afghanistan, increase crop yields and build up a cohort of trained Afghan laborers in a region badly in need of them. (AP Photo/Heidi Vogt)