The First Sea Lord and Chief of Naval Staff of the British Royal Navy, Adm. Sir George Zambellas, second from left, wallks with a U.S. Marine colonel as he prepares to board a Marine Corps MV-22 Osprey tiltrotor aircraft at the Pentagon in Arlington, Va., July 29, 2014. Zambellas is taking part in the Commandant of the Marine Corps' Counterpart Program, which invites foreign military leaders to visit the United States and interact with U.S. military leaders. (U.S. Marine Corps photo by Cpl. Michael C. Guinto/Released)