<P> The Washington Naval Conference, also called the Washington Arms Conference or the Washington Disarmament Conference, was a military conference called by U.S. President Warren G. Harding and held in Washington, D.C., from 12 November 1921 to 6 February 1922 . Conducted outside the auspice of the League of Nations, it was attended by nine nations--the United States, Japan, China, France, Britain, Italy, Belgium, Netherlands, and Portugal--regarding interests in the Pacific Ocean and East Asia . Soviet Russia was not invited to the conference . It was the first international conference held in the United States and the first arms control conference in history, and as Kaufman, 1990 shows, it is studied by political scientists as a model for a successful disarmament movement . </P> <P> Held at Memorial Continental Hall in downtown Washington DC, it resulted in three major treaties: Four - Power Treaty, Five - Power Treaty (more commonly known as the Washington Naval Treaty), the Nine - Power Treaty, and a number of smaller agreements . These treaties preserved peace during the 1920s but were not renewed in the increasingly hostile world of the Great Depression . </P>

Who was involved in the washington naval conference