This study explores the nature of the insurgency in Afghanistan, the key challenges and successes of the campaign, and the capabilities necessary to wage effective counterinsurgency operations. It argues that successful counterinsurgency requires effective indigenous security forces, especially police; a viable and legitimate local government; and the suppression of external support for insurgents.An examination of the U.S.-led campaign in Afghanistan illustrates that successful counterinsurgency requires effective indigenous security forces, especially police; a viable local government; and the suppression of external support for insurgents.