In thus announcing her intention to sink all ships on sight in European waters, Germany burned her bridges behind her. She staked everything on this move. Fully anticipating the hostility of the United States, she hoped to win the war before that country could complete its preparations and give effective support to the Allies. General von Hindenburg's statement has already been quoted. It meant that the army was to assume the defensive, while the navy carried out its attack on Allied communications. Admiral von Capelle, head of the German Admiralty, declared that America's aid would be "absolutely negligible." "My personal view," he added, "is that the U-boat will bring peace within six months." As it turned out, Germany's disregard of neutral rights in 1917, like the violation of Belgium in 1914, reacted upon her and proved the salvation of the Western Powers. After the defection of Russia, France was in imperative need of men. Great Britain needed ships. Neither of these needs could have been supplied save by America's throwing her utmost energies into active participation in the war. This was precisely the result of the proclamation of Feb. 1, 1917. The United States at once broke off diplomatic relations, armed her merchant vessels in March, and on April 6 declared a state of war. Having traced the development of submarine warfare to this critical period, we may now turn to the methods and weapons employed by both sides at a time when victory or defeat hinged on the outcome of the war at sea. Germany's submarine construction and losses appear in the following table from official German sources, the columns showing first the total number built up to the date given, next the total losses to date, and finally the remainder with which Germany started out at the beginning of each year.