U.S. Air Force Staff Sgt. Gary Allsbrook (left) and Senior Airman Michael Van Deusen (right), 455th Expeditionary Security Forces Squadron quick reaction force (QRF), patrol the flightline perimeter, June 27, 2016, Bagram Airfield, Afghanistan. Objectives for members of the QRF is to establish a perimeter around the flightline during an indirect fire, allowing authorized personnel flightline access, and to make sure flightline operations continue uninterrupted. (U.S. Air Force photo by Senior Airman Justyn M. Freeman)