171009-N-FP878-470 ATLANTIC OCEAN (Oct. 9, 2017) The Arleigh Burke-class guided-missile destroyer USS Donald Cook (DDG 75) fires its Mark 45 5-inch gun while conducting a live-fire evolution during exercise Joint Warrior 17-2, Oct. 9, 2017. Joint Warrior is a U.K.-led, multinational exercise that develops interoperability and cooperation in all applicable warfare areas. (U.S. Navy photo by Mass Communication Specialist 1st Class Theron J. Godbold /Released)