(Jan. 21-April 22, 1930) Conference held in London to discuss naval disarmament and review the treaties of the Washington Conference. Representatives of Britain, the U.S., France, Italy, and Japan agreed to regulate submarine warfare and to place limits on new construction of cruisers, destroyers, submarines, and other warships. A treaty limiting battleship size was not signed, and the treaties renewed in 1935 were canceled on the outbreak of World War II