U.S. Air Force Airmen from the 148th Maintenance Squadron await the arrival of F-16s at Thule Air Base, Greenland during North American Aerospace Defense Command’s Arctic air defense exercise, Amalgam Dart 21-2, March 22, 2021. The exercise will run from March 20-26 and range from the Beaufort Sea to Thule, Greenland and extend south down the Eastern Atlantic to the U.S. coast of Maine. Amalgam Dart 21-2 provides NORAD the opportunity to hone homeland defense skills as Canadian, U.S., and NATO forces operate together in the Arctic. (U.S. Air National Guard photo by 2nd Lt. Crystal Kirchner)