U.S. Marines On Operations In Southwest Afghanistan

HELMAND, AFGHANISTAN - APRIL 6: A .50 caliber machine gun points out from a U.S. Marine helicopter flying over the opium poppy fields and the Helmand River April 6, 2009 in Helmand province, Afghanistan. The river irrigates Afghanistan's richest crop, opium poppy, which is later refined into heroin. The illegal crop grown near the Helmand River accounts for the majority of the world's heroin supply. Taliban insurgents, who control much of the Afghan countryside, tax the crop, funding attacks on U.S. troops in Afghanistan. (Photo by John Moore/Getty Images)