US warship, the USS Donald Cook, sails through the Bosporus in Istanbul, Turkey, Thursday, April 10, 2014, en route to the Black Sea. According to a US Department of Defense press release, the guided missile destroyer's deployment is part of " the U.S. commitment to mutual goals in the region," and that it will participate in operations and exercises in the area. Istanbul's two landmarks Haghia Sophia, right, and Blue Mosque are in the background.(AP Photo/Emrah Gurel)