Washington Naval Conference begins

On November 12, 1921, the Washington Naval Conference opened at Memorial Continental Hall in Washington, D.C., after President Warren G. Harding invited the major naval powers to negotiate arms limits. Secretary of State Charles Evans Hughes stunned the delegates from Britain, Japan, France, and Italy by proposing immediate scrapping of capital ships and a fixed battleship ratio for the leading fleets. The conference thus began as a formal diplomatic effort to restrain the expensive naval arms race that had intensified after World War I.

The meeting addressed the interwar tension between pacifist demands for disarmament and the strategic rivalry among the United States, the British Empire, and Japan in the Pacific. Hughes and the Harding administration wanted to avoid both a ruinous shipbuilding competition and a new military confrontation in East Asia, while Japan sought recognition as a major naval power without surrendering its regional influence. The conference also tested whether the United States would use treaty diplomacy rather than League of Nations membership to shape the postwar international order.

The Five-Power Treaty signed in February 1922 followed directly from the conference and established battleship tonnage ratios for the United States, Britain, Japan, France, and Italy. The Four-Power Treaty and Nine-Power Treaty also emerged from the Washington meetings, making the conference the cornerstone of interwar naval arms control and Pacific diplomacy.