A U.S. Air Force pilot from the 555th Fighter Squadron, Aviano Air Base, Italy, smiles during a pre-flight check at Graf Ignatievo Air Base, Bulgaria, Sept. 21, 2020. Thracian Viper 20 provided an opportunity for U.S. Air Force Airmen to train with partners and NATO allies in order to improve interoperability and readiness. Successful partnering activities like this result in progressive relationships and lead to tangible, mutual benefits during peacetime, contingencies and crisis, through actions such as regional security, access and coalition operations. (U.S. Air Force photo by Airman 1st Class Ericka A. Woolever)