I therefore conclude that an unrestricted submarine warfare initiated soon enough to bring about peace before the world harvest in summer 1917 – that is, before August 1 – must hazard the consequences of a break with America, for no other choice remains to us. Despite the danger of a break with America, unlimited submarine warfare, begun soon, is the right means for ending the war successfully. It is also the only means to reach this goal.
Since the fall of 1916, when I declared that the moment had arrived to strike against England, our situation has fundamentally improved. The shortage in the world’s harvest, combined with the effect of the war on England, has once again given us the opportunity to bring about a decision in our favor before the next harvest. If we do not use this opportunity, which according to my calculations will be our last, then I do not see any possibility other than that of mutual exhaustion.
In order to achieve the necessary effect in time, unlimited submarine warfare must begin no later than February 1st. From Your Excellency I request a statement explaining whether the military situation on the continent, especially vis-à-vis those nations which are still neutral, will allow this. I require three weeks for the necessary preparations.
Source: Admiral von Holtzendorff to Field Marshall von Hindenburg (December 22, 1916), reprinted in Herbert Michaelis and Ernst Schraepler, eds., Ursachen und Folgen: vom deutschen Zusammenbruch 1918 und 1945 bis zur staatlichen Neuordnung Deutschlands in der Gegenwart; eine Urkunden- und Dokumentensammlung zur Zeitgeschichte [Causes and Consequences: from the German Collapse in 1918 and 1945 to the New State Organization of Germany in the Present: A Collection of Sources and Documents on Contemporary History]. 29 vols. Berlin: Dokumenten-Verlag, 1959-1979, vol. 2, p. 137-41.
Translation: Jeffrey Verhey