A U.S. Air Force F-16 Fighting Falcon assigned to the 555th Fighter Squadron, Aviano Air Base, Italy, participates in exercise Thracian Viper 20 at Graf Ignatievo Air Base, Bulgaria, Sept. 23, 2020. Thracian Viper 20 is a multilateral training exercise with the Bulgarian air force, aimed to increase operational capacity, capability and interoperability with Bulgaria. Exercises like this enhance their ability to rapidly deploy to a remote location, establish command and control and deliver lethal airpower more effectively and efficiently anywhere in the world. (U.S. Air Force photo by Airman 1st Class Ericka A. Woolever)