A Bulgarian Land Forces tank moves to an objective during a combined arms live fire exercise titled Peace Sentinel at Koren, Bulgaria, on July 19. Exercise Saber Guardian 17 is a U.S. European Command, U.S. Army Europe-led exercise in the Black Sea Region that builds readiness and improves interoperability among the 20 Allies who participate. (U.S. Army photo by Spc. Thomas Scaggs) 170717-A-TZ475-295