La Fontaine took an early interest in the International Peace Bureau, founded in 1882, and was influential in the Bureau's efforts to bring about The Hague Peace Conferences of 1899 and 1907. He served as President of the Bureau from 1907 until his death in 1943. World War I convinced La Fontaine that the world would establish an international court when peace returned. He proposed a number of possible members, including Joseph Hodges Choate, Elihu Root, Charles william Eliot, and Andrew Dickson White. La Fontaine also promoted the idea of unification of the world's pacifist organizations.