Marines from the first Battalion, 6th re

Marines from the first Battalion, 6th regiment take cover after hearing bullets whizzing during a patrol in the outskirts of Marjah in central Helmand on 19 January, 2010. The crisp crackling of AK-47s breaks the morning silence as US Marines inch towards the outskirts of a Taliban stronghold in Afghanistan's southern province of Helmand.The Marines are on one of the patrol missions to inch closer to Marjah in Helmand province, which produces the bulk of the world's opium poppy, the main ingredient in the production of heroin.AFP PHOTO/CHRISTOPHE SIMON (Photo credit should read CHRISTOPHE SIMON/AFP via Getty Images)