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Chief of the Admiralty Staff Admiral Henning von Holtzendorff, German Imperial Marine Service, to Chief of the Army General Staff General Field Marshal Paul von Hindenburg

Strictly confidential.                  Berlin, December 22, 1916.

     I have the honor to transmit most respectfully to your Excellency the attached statement of the necessity of an early launching of the unrestricted U-boat war. The document in question is, in the main, a continuation of the memorial of the 27th of August, 1916, which was entitled “The Cargo Space Question and England’s Supply for the Year 1916,” and which was sent to your Excellency.1

     On the basis of the detailed statements in the draft in question, I will ask your Excellency to examine the reasoning which is followed, and hope that we shall reach a full agreement to the effect that it is absolutely necessary to adopt the severest measures possible against England’s ocean commerce at the earliest practicable moment in order to make the best possible use of the advantages of the present situation and to assure ourselves an early victory.


     It is necessary that the war be fought out to a definite decision before August, 1917, unless it is to result in the exhaustion of all the belligerents, and hence in a termination that will be fatal for us. Our enemies Italy and France have received such a staggering blow, economically speaking, that it is only by the energy and force of England that they are still kept on their feet. If we can succeed in breaking the backbone of England’s resistance, the war will immediately be terminated in our favor. But the backbone of England consists in the cargo space used for bringing to England those imports necessary for the maintenance of life, which assure her credit in foreign countries.


     The stand taken with regard to cargo space, in the document of the 27th of August to which I have already referred, which subject was gone into in detail at that time, is again set out in the annexed enclosure. In brief it is this: Freight rates for the transportation of a great number of essential commodities have risen to an enormous extent, even being increased tenfold or more. We know absolutely from numerous other sources that there is a general shortage in cargo space.

     The English tonnage existing even at the present moment may be correctly assumed to be about 20 million tons gross. At least 8.6 million tons have been requisitioned for military purposes, and a half million is engaged in the coastwise trade, and according to estimates one million are under repairs, and therefore unavailable at the present time; some 2 million tons are designated for the use of the Allies, so that at the very most there are still 8 million tons of English shipping available for supplying England with foodstuffs. If we examine the statistics of the sea commerce in the British ports, the result is even less. In the months of July and September, 1916, according to these statistics, only about 6.75 million gross tons of English cargo space docked in England. In addition to this, there are about 900,000 tons of shipping engaged in commerce with England—enemy shipping, not British—and perhaps 3 million tons of neutral shipping. Altogether, then, England’s food supply is taken care of by only some 10.75 million gross tonnage, roughly speaking.


     If the work which we have done thus far in our war against cargo space is such as to hold out good prospects for further steps along this line, we may say that the abnormally poor results all over the world of this year’s harvest of breadstuffs and provender has place in our hands a very unique opportunity, of which no one will dare assume the responsibility of failing to take advantage.

     Starting, apparently, as early as February, North American and Canada will be in a position of having practically no wheatstuffs at all to spare for the purposes of England. In this case, England must depend for its food supply on Argentina, separated as it is from England by a long trip, and since Argentina, as the result of its poor harvest, will be able to deliver but little, India and particularly Australia must be England’s sources of supply. It is shown in detail in the enclosure how the increased distance of the route to be traversed will result in an increasing demand upon our enemies for cargo space for grain to the extent of 720,000 tons. The practical result of this is that, of the available 10.75 million tons, 750,000 will be needed up to August, 1917, for a service which, up to this time, has not been required.


     Under conditions such as these, so favorable to us, an energetic blow delivered with all the strength at our command against English cargo space gives promise of an absolute certainty of success, so that I can only repeat and most pointedly emphasize my assertion of August 27, 1916, that “our obvious military task consists in the act of now bring about a decision in our favor by the destruction of cargo space” and further, that “from the military standpoint there is no justification in refraining from the use, even at the present time, of the U-boat weapon.” I do not hesitate to declare that as things stand at present, England will be forced to sue for peace within five months as the result of launching an unrestricted U-boat war. But this is true only in case ruthless U-boat warfare is carried on; it would not follow as the result of the limited U-boat war on commerce which is being carried on at this time, even if all armed vessels were to be considered as open to attack.


     Proceeding on the basis of the monthly estimate already submitted of the computed destruction of 600,000 tons of cargo space by means of the unrestricted U-boat war, and on the basis of the expectation, more detailed figures in support of which are set out in the enclosure, that by means of such warfare at least two fifths of the neutral ocean commerce would be intimidated to the extent of not even setting sail for England, we may calculate that after the termination of five months English ocean trade will have fallen behind what it is today by some 39 per cent. England would not be able to put up with such a loss, whether considered with regard to its effects upon the situation which would develop after the war or with regard to the possibility of continuing further with the war at the present time. Today England is facing a situation as to foodstuffs which forces her, as a last resort, to attempt to put into operation those measures which we, in our position as a blockaded country, have had to adopt during the course of the war. The setting for an organization of this kind in England is entirely and fundamentally different from our own, and, as a matter of fact, unspeakably more unfavorable than is the case with us. The authority is lacking, and the education of the people is such that they have not the discipline essential to meet such a pinch. And for another reason, too, it is no longer possible for the entire population of England to be put on the system of short rations in breadstuffs demanded by the situation. It is possible in Germany when we could substitute for the sudden bread shortage other temporary means of subsistence. This moment has gone by for England, and nothing can bring it back again. The supplying of England with the necessary foodstuffs can not be brought about by means of some three fifths of ocean transportation available without a corresponding powerful limitation upon the use of breadstuffs—and in this connection we must bear in mind the necessity of keeping the war industries going at the same time. The suggestion that England may already have in the country a sufficient amount of foodstuffs to tide over the crisis until the next harvest, is shown in the enclosure to be absolutely without merit.

     Moreover, add the fact that the unrestricted U-boat war would at once mean a famine in fats for England, together with the cessation of the supply from Denmark and Holland, since a third of the entire importations of butter from England come from Denmark and all the imported butter-fats come from Holland. Further, it would mean an increased shortage of metals and woods as the result of the menace against the importations of metal and wood from Scandinavia going hand and hand with increased menace to shipment of metal from Spain. As a result, coal mining would decrease instantly, as the wood necessary for that purpose would no longer be available, and such would also be the case with iron and steel products and munitions dependant upon both of them. Finally, it would give us the opportunity so long desired to take effective steps against the importation of ammunition by neutrals, and to that extent to ease the burdens of the army.

     In contrast with the above, a limited U-boat war on commerce, even in connection with the general release of armed steamers, would, after five months, have cut down the shipping engaged in the British trade by only five times 400,000 tons—about 18 per cent of the present monthly ocean trade, and thus less than 50 per cent of the results of the unrestricted U-boat warfare. Judging by past experiences, we can be by no means certain of the fact that the release of armed steamers would increase the cargo space sent to the bottom to any appreciable extent over the average of 400,000 tons reached in the last two months. It is probable that it will rather only counterbalance the loss otherwise to be expected by reason of increased arming. I am perfectly clear on the point that even the falling away of about one fifth of the present ocean commerce would have very disturbing results on the question of England’s food supply. But I consider it impossible that England, now subject to the guidance of Lloyd George’s policy of holding out to the very end, could be forced to sue for peace if the effects of the shortage of fats, woods and metals above referred to, and the continued undermining of munition imports, should not be availed of. Add to this the cessation of the psychological effects of panic and fear. These effects, which can be brought about only as the result of ruthless U-boat warfare, constitute in my opinion an absolutely essential prerequisite of success. The experiences which were ours in the beginning of the U-boat war in the spring of 1915, when the British believed that it was being carried on in dead earnest, show the weighty importance of these effects, as do our experiences of the short U-boat war of March and April, 1916.

     It is further necessary, as a prerequisite, that the unrestricted U-boat war should commence at the time that it is announced, and that no time be left for preparations, particularly between England and the neutral Powers. It is only in such case that great fear will be injected into the enemy and into neutrals as well.


     The announcement of the unrestricted U-boat war will bring the Government of the United States of American once more face to face with the question of whether or not it will maintain the same position regarding the question of the use of U-boats which, judging from its attitude, it has maintained up to this time. I am positive in the opinion that war with the United States is so serious a question that all steps should be taken to avoid it. But in my opinion also the fear of such a break should not overawe us at the crucial moment to the extent of causing us to renounce the use of the weapon which promises us victory.

     In any case, it is expedient for us to assume the solution more unfavorable to us and to clear up our own mind on the question of the effect which the entrance of the United States into the war would have on the result of the war, as far as our opponents are concerned. This effect could at best be practically negligible with regard to shipping space, It is not be be expected that more than an inconsiderable fraction of the tonnage belonging to the Central Powers now lying in American ports, and perhaps also other neutral ports, would at once be put in use for commerce with England. It would be quite possible to damage the greater part thereof so seriously that it would not be seaworthy in the critical period of the first few months. Arrangements have been made to bring this result about; moreover, it would be next to impossible to obtain crews for these ships. We may attribute an equal paucity of results in the case of American troops which, on account of absence of cargo space, would not be able to be brought over in any considerable numbers; and to American money, which can never take the place of transportation and shipping space. The only question to be considered is the attitude which America would assume towards the question of concluding peace—the peace for which England would be forced to sue. We can not suppose that the United States would then determine to carry on the war against us single-handed, as it has no means at its disposal for taking definite steps against us, whereas its commerce would be damaged by our U-boats. On the other hand, it is to be expected that the United States would support the conclusion of such a peace, in order to resume normal commercial relations at the earliest possible moment.

     I therefore reach the conclusion, that an unrestricted U-boat war so correctly timed as to bring about peace before the gathering of the harvest of the summer of 1917, that is to say, before August I, will have to be at the cost of a break with the United States, for the reason that we are left no other choice. It follows that in spite of the danger of a break with America, an unrestricted U-boat war, promptly launched, is the proper means of winning the war. Moreover, it is the only means to this end.


     Ever since I announced in August, 1916, that the time had come for dealing a crushing blow to England, the situation has materially changed to our advantage. The falling off of crops all over the world, taken in connection with the effect of the war on England up to this time, affords us once more the opportunity of bringing about a decision in our favor before the new crops are gathered. If we fail to make use of this opportunity, which so far as can be foreseen, is our last, I can see no alternative that that of mutual exhaustion, without its being possible for us to terminate the war in such a way as to guarantee our future as a world Power.

     In order to obtain the necessary results in time, the unrestricted U-boat war mush commence by February I at the latest. I ask your Excellency to inform me as to whether the military situation on the Continent, particularly in regard to those Powers who still remain neutral, is such as to make this date convenient. I shall need three weeks time for the necessary preparations.2

v. Holtzendorff

Source Note: Official German Documents Relating to the World War Translated under the supervision of the Carnegie Endowment for International Peace Division of International Law, 2 vols. (New York, Oxford University Press, 1923), 2: 1214-19. This document lays out the rationale for German resumption of unrestricted submarine warfare. According to historian Holger H. Herwig this document was unique because to create it Holtezendorff “gathered in . . . a small army of experts – the equivalent of a modern-day ‘think tank’- to make his case.” Those experts were “a seemingly irrefutable cross-section of Germany’s leading financial, commercial, agrarian, and industrial leaders. For the first time in modern German history, a national grand strategy was devised by committee.” Herwig, “Total Rhetoric, Limited War: Germany’s U-Boat Campaign, 1917-1918,” in Great War, Total War: Combat and Mobilization on the Western Front, 1914-1918, Roger Chickering and Stig Förster, eds. (New York, German Historical Institute and Cambridge University Press, 2000), 194. In that same article, Herwig lists key misconceptions in the plan that allowed Great Britain to survive unrestricted submarine warfare despite the fact that German U-boats destroyed the amount of tonnage that Holtzendorff predicted would be enough to force Britain to sue for peace. Ibid., 199-205.

Footnote 1: For more on this memorandum, see Official German Documents Relating to the World War Translated under the supervision of the Carnegie Endowment for International Peace Division of International Law, 2 vols. (New York, Oxford University Press, 1923), 1152-63.

Footnote 2: The decision to resume unrestricted submarine warfare was made on 9 January 1917 in a meeting at army headquarters. The day before Hindenburg, speaking on behalf of the German army, had announced: “We fully expect war with American and have made all preparations for it. The situation cannot get any worse.” Quoted in Holger H. Herwig, Politics of Frustration: The United States in German Naval Planning, 1889-1941 (Boston, Little, Brown and Company), 122. The German Ambassador to the United States announced the new policy to American Secretary of State Robert Lansing on 31 January, and on 3 February, President Woodrow Wilson informed a joint session of Congress that he had broken diplomatic relations with Germany, although he did not at that time ask for a declaration of war. See: Robert Lansing, Memorandum on the Severance of Diplomatic Relations with Germany, 4 February 1917.

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