150715-N-AT895-185 LONDON (July 15, 2015) Chief of Naval Operations (CNO) Adm. Jonathan Greenert and First Sea Lord of the Royal Navy Adm. Sir George Zambellas participate in a moderated talk focused on the future of the British-American naval alliance at Chatham House, the Royal Institute of International Affairs. Chatham House is an independent policy institute based in London. (U.S. Navy photo by Mass Communication Specialist 1st Class Nathan Laird/Released)