naval conferences, series of international assemblies, meeting to consider limitation of naval armaments, settlement of the rules of naval war, and allied issues. The London Naval Conference (1908–9), composed of delegates of 10 powers, resulted in the influential Declaration of London (see London, Declaration of). After World War I, U.S. President Harding called the Washington Conference (1921–22). Several treaties resulted. The Five-Power Treaty limited tonnage of aircraft carriers and capital ships and arranged for the United States, Great Britain, and France to scrap a number of ships. Agreement was reached on a ratio of capital ships for Great Britain, the United States, Japan, France, and Italy; the ratio was set at 5:5:3:1.67:1.67. Another five-power treaty made the rules of warfare applying to surface ships applicable also to submarines and outlawed the use of poison gas. In the Four-Power Treaty, France, Japan, Great Britain, and the United States agreed to respect each other's possessions in the Pacific. The status quo of naval fortifications in the W Pacific was to be maintained. Japan was to return Shandong to China, which was guaranteed territorial integrity and greater control over its tariff by two Nine-Power Treaties. The Washington Conference treaties were to remain in force until Dec. 31, 1936. The Geneva Conference (1927) failed to reach agreement on more comprehensive limits for warships. At the London Conference (1930), Japan won a 7:10:10 ratio with the United States and Great Britain in small cruisers and destroyers, remained at a 3:5:5 ratio with them in large cruisers, and won parity in submarines. France and Italy refused to take part in the new ratios, but, with the other three powers, agreed to defer further construction of capital ships. An escalator clause provided for naval expansion in case of any threat to national security by the naval building of a nonsignatory nation. The announcement in 1934 of Japan's intention to withdraw from the Washington Conference treaties resulted in another London Conference (1935). Japan withdrew from the conference when refused naval parity with the United States and Great Britain. These two powers and France signed (Mar. 25, 1936) an agreement to limit cruisers and destroyers to 8,000 tons and capital ships to 35,000 tons. Reports of Japanese building in excess of 35,000 tons led to a revision (1938) of the treaty limits on the size of capital ships, and with the outbreak of World War II in 1939 the treaties were completely abandoned.