181031-N-PJ225-0001 PHILIPPINE SEA (Oct. 31, 2018) Sailors assigned to the Arleigh Burke-class guided-missile destroyer USS Curtis Wilbur (DDG 54) prepare to chalk and chain a Japan Maritime Self-Defense Force (JMSDF) helicopter for an acquisition and cross servicing agreement logistics exchange during exercise Keen Sword 19, Oct. 31, 2018. Keen Sword is a joint, bilateral field-training exercise involving U.S. military and JMSDF personnel, designed to increase combat readiness and interoperability of the Japan-U.S. alliance. (U.S. Navy photo by Lt. j.g. Emily Cooper/Released)