Rumen Radev, president of Bulgaria, left, and two U.S. Air Force pilots from the 555th Fighter Squadron, talk in front of a U.S. Air Force F-16 Fighting Falcon during Thracian Viper 20 at Graf Ignatievo Air Base, Bulgaria, Sept. 24, 2020. During Thracian Viper 20, U.S. and Bulgarian air forces will conduct training to enhance their ability to rapidly deploy to remote locations and take command and control of the region. (U.S. Air Force photo by Airman 1st Class Ericka A. Woolever)