31 JANUARY 1917 â Germany announces the renewal of unlimited submarine warfare in the Atlantic, and German torpedo-armed submarines prepare to attack any and all ships, including civilian passenger carriers, said to be sited 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.
MILITARY HISTORY SOCIETY OF ROCHESTER
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