(A U.S. Marine in Marjah, picture by Goran Tomasevic)

(A U.S. Marine in Marjah, picture by Goran Tomasevic)

One of the reasons the bigĀ U.S.-led offensive in Afghanistan's Marjah area has slowed down is because the Marines are trying to avoid civilian casualties at all costs, according to military commanders. So use of air power, the key to U.S. battle strategy, has been cut back because of the risk of collateral damage from strikes.