Sussex Pledge: It prompted President Woodrow Wilson to declare that if Germany were to continue this practice, the United States would break diplomatic relations with Germany. The Sussex pledge, which promised a change in Germany’s naval warfare policy. The primary elements of this undertaking were:Passenger ships would not be targetedMerchant ships would not be sunk until the presence of weapons had been established, if necessary by a search of the shipMerchant ships would not be sunk without provision for the safety of passengers and crew.In 1917 Germany became convinced they could defeat the Allied Forces by instituting unrestricted submarine warfare before the United States could enter the war. The Sussex pledge was therefore rescinded in January 1917, thereby initiating the decisive stage of the so-called First Battle of the Atlantic. The resumption of unrestricted submarine warfare and the Zimmerman Telegram caused the United States to declare war on Germany on April 6, 1917.

Sussex Pledge