ATLANTIC OCEAN (May 16, 2021) The Arleigh Burke-class guided-missile destroyer USS Paul Ignatius (DDG 117) fires a MK-45 MOD 4 5-inch 62 caliber lightweight gun as part of a live-fire exercise during exercise At-Sea Demo/Formidable Shield, May 16, 2021. Exercise At-Sea Demo/Formidable Shield is a joint live-fire integrated air and missile defense (IAMD) exercise conducted by Naval Striking and Support Forces NATO on behalf of U.S. 6th Fleet. (U.S. Navy photo by Mass Communication Specialist 2nd Class Nathan T. Beard)