Germany Resumes Unrestricted Submarine Warfare

Germany announced it would resume unrestricted submarine warfare, sinking all ships—including neutral American vessels—in the war zone around Britain. Germany calculated it could starve Britain into defeat within 5 months before American intervention could take effect. The policy sank 860,000 tons of Allied shipping in April 1917 alone—nearly achieving its aim. It also proved the decisive factor in drawing the United States into the war.