150312-N-JN664-264 ROTA, Spain (March 12, 2015) Sailors assigned to USS Donald Cook (DDG 75) participate in sentry reaction force training March 12, 2015. Donald Cook, an Arleigh Burke-class guided-missile destroyer forward-deployed to Rota, Spain, is conducting naval operations in the U.S. 6th Fleet area of operations in support of U.S. national security interests in Europe. (U.S. Navy photo by Mass Communication Specialist 2nd Class Karolina A. Oseguera/Released)