A U.S. Air Force C-17 Globemaster III aircraft assigned to the 437th Airlift Wing, Joint Base Charleston, South Carolina, drops Air Force and U.S. Army paratroopers onto Cheshnegirovo Airfield, Bulgaria, during exercise Swift Response 21, May 11, 2021. Rapid airfield security, assessment and performance of initial airfield operations enabled joint delivery of troops and heavy equipment cargo in a simulated contested environment. (U.S. Air Force photo by Senior Airman John R. Wright)