In 1917, Germany, determined to win its war of attrition against the Allies, announced the resumption of unrestricted warfare in war-zone waters. Three days later, the United States broke diplomatic relations with Germany, and just hours after that the American liner Housatonic was sunk by a German U-boat.
Even after announcing the diplomatic break on February 3, 1917, Wilson still signaled that the United States would stay out of the war as long as the Germans did not target American vessels.
