Two Republic of Korea Air Force F-16D Fighting Falcons fly during a training exercise Oct. 8, 2019. The 909th Air Refueling Squadron from Kadena Air Base trains with ROKAF periodically to enhance readiness and joint force lethality. Both the United States and Republic of Korea continue to develop interoperability through the use of annual joint and combined exercises such as Ulchi Freedom Guardian, Key Resolve, and Foal Eagle. (U.S. Air Force photo by Senior Airman Cynthia Belío)