Unlimited U-Boat warfare

The German Reich has been in the stranglehold of the British naval blockade since the outbreak of the First World War. By the third year of the war the situation has become critical: The critically necessary raw materials for armaments production are running out. It is becoming increasingly more difficult to import food, and the German people are starving. In this situation the Supreme Military Command in Berlin (OHL) makes a decision fraught with consequences: Since Great Britain is even more dependent on open maritime routes,  Germany illegally resumes unlimited U-boat warfare on 1 February 1917 for the purpose of forcing that nation to its knees.

© Deutsches Historisches Museum, Berlin German U-Boat opening fire on a hostile steamship

With this decision Berlin takes into account the previously neutral USA’s very likely entry into the war. By 3 February 1917, Washington breaks off diplomatic relations with Berlin. Two months later, on 6 April 1917, the United States declares war on the German Reich. Nearly inexhaustible material reserves and contingents of fresh troops from the United States will finally decide the war in favour of the Entente.