Japan 's participation in World War I on the side of the Allies sparked unprecedented economic growth and earned Japan new colonies in the South Pacific seized from Germany . After the war Japan signed the Treaty of Versailles and enjoyed good international relations through its membership in the League of Nations and participation in international disarmament conferences . The Great Kantō earthquake in September 1923 left over 100,000 dead , and combined with the resultant fires destroyed the homes of more than three million
Great Kantō earthquake
1923 Great Kantō earthquake
History of Japan