A U.S. Air Force pilot from the 555th Fighter Squadron briefs Bulgarian leadership during Thracian Viper 20 at Graf Ignatievo Air Base, Bulgaria, Sept. 24, 2020. Thracian Viper is a multilateral training exercise with the Bulgarian air force, aimed to increase operational capacity, capability and interoperability with Bulgaria. (U.S. Air Force photo by Airman 1st Class Ericka A. Woolever)