A defender with the 99th Security Forces Squadron trains on how to secure an airfield during the Air Force Installation and Mission Support Center’s final Combat Support Training Range proof of concept at Fort Bliss, Texas, Aug. 16, 2023. The CSTR initiative expands multi-functional training opportunities for installation and mission support Airmen to practice for future adaptive operations and agile combat employment in contested environments and austere locations. (U.S. Air Force photo by Malcolm McClendon).