Nine-power Treaty
Nine-power Treaty, February 6, 1922, a treaty signed at Washington, D.C. The signers were China and the United States, Great Britain (for the British Empire), Japan, Italy, France, Belgium, Portugal, and the Netherlands, who agreed to respect the sovereignty, independence, and territorial and administrative integrity of China. They committed themselves to the Open Door policy of equal opportunity for the commerce and industry of all nations in China. Japan violated the treaty by invading Manchuria in 1931.