Sussex pledge

The ship was severely damaged and about 80 people died,[1] including the famous Spanish pianist and composer Enrique Granados.

US President Woodrow Wilson declared before Congress that the German were breaching their assurances once again, that past assurances "has in fact constituted no check at all upon the destruction of ships of every sort", and that if the Germans sought to argue that submarines could not be used except by means "incompatible with the principles of humanity", and used them nevertheless, the United States would break diplomatic relations with Germany.

These were the primary elements of the pledge: In 1917, Germany became convinced that it 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The Sussex pledge was, therefore, rescinded in January 1917, which started the decisive stage of the so-called First Battle of the Atlantic.

The resumption of unrestricted submarine warfare and the Zimmermann Telegram caused the United States to declare war on Germany on April 6, 1917.