While respected internationally, the Open Door Policy was ignored by Russia and Japan when they encroached in Manchuria. The U.S. protested Russia's actions. Japan and Russia fought the Russo-Japanese War in 1904, in which the U.S. mediated a peace. Japan also presented a further challenge to the policy with its Twenty-One Demands in 1915 made on the then-Republic of China. Japan also made secret treaties with the Allied Powers promising Japan the German territories in China. In 1931, Japan invaded and occupied Manchuria. The United States along with other countries condemned the action, leading to U.S. support for China in its war with Japan after 1937.