At the outbreak of World War I in 1914, Wilson maintained a policy of neutrality between the Allied and Central Powers. He narrowly won re-election in the 1916 United States presidential election, defeating Republican nominee Charles Evans Hughes. In April 1917, Wilson asked Congress for a declaration of war against the German Empire in response to its policy of unrestricted submarine warfare, Congress complied. Wilson presided over war-time mobilization but devoted much of his efforts to foreign affairs, developing the "Fourteen Points" as a basis for post-war peace. After the Allied victory in November 1918, Wilson and other Allied leaders took part in the Paris Peace Conference, where Wilson advocated for the establishment of a multinational organization. The resulting League of Nations was incorporated into the Treaty of Versailles. However, Wilson was unable to convince the U.S. Senate to ratify the treaty or allow the United States to join the League. Wilson had intended to seek a third term in office but suffered a severe stroke in October 1919 that left him incapacitated for most of what was left of his presidency. He retired from public office in 1921 and died in 1924 at the age of 67.