In early 1917, Wilson asked Congress for a declaration of war against the German Empire after it implemented a policy of unrestricted submarine warfare, and 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 Germany signed an armistice in November 1918, Wilson and other Allied leaders took part in the Paris Peace Conference, where Wilson advocated for the establishment of a multilateral organization, per his 'fourteenth point'. The resulting League of Nations was incorporated into the Treaty of Versailles and other treaties with the defeated Central Powers, but Wilson was subsequently unable to convince the Senate to ratify that treaty or allow the United States to join the League. Wilson suffered a severe stroke in October 1919 and was incapacitated for the remainder of his presidency. He retired from public office in 1921 and died in 1924. Scholars have generally ranked Wilson as one of the better U.S. presidents, though he has received strong criticism for his actions regarding racial segregation.