Army Command Sgt. Maj. William F. Thetford, left, U.S. Central Command's senior enlisted advisor, speaks with a security forces soldier during a visit to Forward Operating Base Oqab in Kabul, Afghanistan, Aug. 15, 2017. Thetford met with airmen and soldiers at Train, Advise, Assist Command-Air to review the progress of the Afghan air force and survey the welfare of service members assigned to the TAAC-AIR mission. Air Force photo by Staff Sgt. Alexander W. Riedel