U.S. Air Force Col. Mark Koppen takes a photo with the Washington Redskins cheerleaders of the NFL at the U.S. Air Force base Ali Al Salem near Kuwait City December 16, 2011. U.S. forces formally ended their nine-year war in Iraq on Thursday with a low key flag ceremony in Baghdad, while to the north flickering violence highlighted ethnic and sectarian strains threatening the country in years ahead. REUTERS/Shannon Stapleton (IRAQ - Tags: MILITARY CONFLICT SOCIETY)