Joint Base Andrews security forces Airmen begin a timed 1.5 mile run on JBA, Md., July 23, 2018. The defenders are competing for the opportunity to represent the Air Force District of Washington in the Defender Challenge 2018 at Camp Bullis, San Antonio, Texas. The challenge will give the Air Force and partnering allies such as the Royal Air Force, the German Luftwaffe, the Royal Australian Air Force and the Royal Canadian Air Force a way to showcase their military police capabilities and joint interoperability. (U.S. Air Force photo by Airman 1st Class Michael S. Murphy)