U.S. Sailors aboard the guided missile destroyer USS Curtis Wilbur (DDG 54) prepare to receive fuel from the dry cargo and ammunition ship USNS Matthew Perry (T-AKE 9) during exercise Foal Eagle 2014 in the Pacific Ocean March 12, 2014. Foal Eagle is a combined U.S.-South Korea field training exercise held annually in South Korea to ensure the operational readiness of air, space and cyberspace operations in the Korean theater of operations.