ATLANTIC OCEAN (May 20, 2021) The Arleigh Burke-class guided-missile destroyer USS Paul Ignatius (DDG 117) transits the Atlantic Ocean during exercise At-Sea Demo/Formidable Shield, May 20, 2021. Exercise At-Sea Demo/Formidable Shield, conducted by Naval Striking and Support Forces NATO on behalf of U.S. 6th Fleet, is a live-fire integrated air and missile defense (IAMD) exercise that improves Allied interoperability using NATO command and control reporting structures. (U.S. Navy photo by Mass Communication Specialist 2nd Class Nathan T. Beard)