A diplomatic agreement between Britain and Japan. It improved Britain’s international position and consolidated Japan’s position in north‐east Asia at a time of increasing rivalry with Russia. The two powers agreed to remain neutral in any war fought by the other to preserve the status quo and to join the other in any war fought against two powers. Britain and Japan began to drift apart after World War I, and when the Washington Conference was summoned in 1921, Britain decided not to renew the alliance, which ended in 1923.