The government operated a Canadian War Mission in Washington, 1918 to 1921, but it was not until William Lyon Mackenzie King became Prime Minister in 1921 that Canada seriously pursued an independent foreign policy. In 1923, Canada independently signed the Halibut Treaty with the United States at Mackenzie King's insistence – the first time Canada signed a treaty without the British also signing it. In 1925, the government appointed a permanent diplomat to Geneva to deal with the League of Nations and International Labour Organization. Following the Balfour Declaration of 1926, King appointed Vincent Massey as the first Canadian minister plenipotentiary in Washington (1926), raised the office in Paris to legation status under Philippe Roy (1928), and opened a legation in Tokyo with Herbert Marler as envoy (1929).