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UNRESTRICTED SUBMARINE WARFARE STRATEGY; THE GERMAN DILEMMA

“The views expressed in this article are those of the author and do not reflect the official policy or position of the National Defense University, the Department of Defense, or the U.S. Government.”

“Even if a submarine should work by a miracle, it will never be used. No Country in this World would ever use such a vicious and petty farm of warfare!”
-William Henderson, British

“War is cruelty. There’s no use trying to reform it; the crueler it is the sooner it will be over.”
-William Tecumseh Sherman

In 1864 the Confederate submersible H.L. HUNLEY used an improvised spar torpedo to sink USS HOUSATONIC in Charleston Harbor, and the birth of undersea warfare began. However it was somewhat of a premature birth, i.e., we don’t sec further use in war time until the beginning of WWI. As the ‘Great War’ began to cast its dark clouds over the world, a new and unproven technology was on the doorstep of Kaiser Wilhelm 11 and the Imperial German Navy. In this paper I will outline and detail the events and circumstances that would place the German leadership in an unenviable position of developing and implementing a strategy that would forever determine their fate. Indeed, could German leadership possibly make a rational decision regarding the implementation of unrestricted submarine warfare during WWI?

When Germany entered WWI in August of 1914, it had in service 28 (Unterseeboote) U-boats. The first boat Ul had completed its initial sea trials only seven years earlier in 1907, and the next three subsequent boats were not of sufficient design to contribute to any war fighting capability; however, all four of the initial class were utilized during the war as training platforms. Therefore, units US through U28 would comprise Germany’s starting lineup as the war began.

Throughout the period 1914-1918, multiple boats were in various stages of construction and the German industrial base and shipyards would continue to produce U-boats during the entirety of the war. Various design improvements were continually being incorporated and along with construction of larger overseas boats, which were more capable longer range vessels, the fleet was also being joined by smaller UB class boats intended to perform coastal defense missions and UC class boats which were specifically designed for mine laying missions.

The Germans had mastered the submarine construction process with the ability to prefabricate sections and then simply assemble the sections. According to V .E. Terrant, “a total of 178 U-boats were destroyed during the war (of which nineteen were lost by accidental causes) the Germans were still in possession of 171 U-boats at the time of the armistice, with a further 149 in various stages of construction.”1 It is obvious that the production of U-boats was clearly not a factor in the way they were used throughout the war.

Looking at it in hindsight, it certainly would have been devastating to Great Britain, if production leading up to the war had been increased. However, that would have required a pre-dcveloped strategy for use of such a weapon and in reality, as Tarrant writes, “at this time the German Naval Staff (Admira/stab) had little faith in the capabilities of their Unterseeboote and small understanding of their formidable latent potentialities. Indeed, the initial strategic role they perceived for the undersea arm was purely defensive.”

Two days after Great Britain declared war (4 August 1914) ten German U-boats got underway on what would be the first German U-boat war patrol. Their primary mission was intelligence, surveillance, and reconnaissance (ISR) and secondarily to engage the enemy if sighted. Of the initial ten boats, one had to return to port with mechanical problems as the remaining nine moved north. Somewhat dismayed, they approached what was believed to be the British blockade line, but to this point had yet to sight the British battle fleet. It was two days into their patrol, before a single British ship was sighted. Upon sighting of the British warships U I 5 attempted to engage the British battleship Monarch with a torpedo, only to have it miss its target. However, this effort resulted in alerting the British of the eminent danger. The advantage of surprise was now lost as night fell. The next morning bad luck would have U I 5 idling on the surface as her crew attempted to make mechanical repairs. Unfortunately for her, she was sighted by the British light cruiser Birmingham, who proceeded to ram and sever the U-boat into two halves, sending the boat and her crew to the bottom.

As the U-boats returned to Germany three days later, only seven of the original nine returned. It was believed that in addition to the loss of U I 5, the unlucky U 13 had struck a mine and was lost at sea. Terrant summarizes, “The results of this pioneer operation did very little to vindicate the value of the Unterseeboote in the eyes of the Admiralstab. They had failed to damage, let alone sink a single enemy warship, yet had lost two of their number in the attempt.

However, success was less than a month away. On September 5, 1914, U21 made history by sinking the first warship with a fired torpedo. This event was quickly topped on September 22, when U9 launched an attack and sank three British cruisers in under an hour, with an estimated loss of over I, I 00 men. This significant event captured the immediate attention and concern of the British Admiralty. R.H. Gibson and Maurice Prendergast point out, “As a result of this triple sinking, the Cruiser Squadron was abolished; a mine field was laid on October 2, about fifty miles north of Os tend, ….. by the end of the year some 2000 British mines had been planted. ”

An even more important development occurred in November, as the Grand Fleet port of Scapa was infiltrated by a German U-boat. This event coupled with numerous false sightings of peri-scopes sent the British fleet scrambling north to Scotland for weeks at a time. The enormous significance of this development was summarized by Gibson and Prendergast:

It meant that a few submarines had forced the most powerful battle-fleet in history to abandon its base and retreat to a second base. and then to a third, each being progressively more remote and from the main theater of naval hostilities -the North Sea… In a word, the bottom of the whole strategical situation was knocked out for a time by the German U-boats … Well was it for us that the Germans failed to seize the enormous opportunity lying within her reach. ”

Germany’s initial strategy regarding the use of the submarine was indicative of the fact that tfiey dicf not clearly understand the shear power and potential of the implement of war they possessed. However, following this first phase of submarine operations, no one could doubt the lethality of the German U-boat. “The Germans had found in their hands a weapon wherewith they could strike at their enemy with a freedom denied to their surface ships”

Here before Imperial Germany was possibly the Holy Grail; the ultimate answer to their problem of how to end the blockade of Germany and bring the war to a close. Or, ironically was it merely a tin cup that would eventually lead to the ultimate downfall of Germany.

Germany was faced with the age old conflict of military versus statesman by the onset of this new technology and its potential use. Great debate concerning the strategy and method of use in regards to Germany’s submarines had been occurring continuously since the beginning of the war. Lines between the military and state had been drawn early and would continue to hamper a decision in regards to a definitive German submarine strategy. There was a very distinct difference of opinion over the manner in which the submarine arm should be utilized.

Kaiser Wilhelm II had made his position known concerning the matter-at least initially. His position at the being of the war indicated that he clearly had reservations about the way in which the submarine arm would be prosecuted. His fear like many others in Germany’s diplomatic circles was that a declaration of unrestricted submarine warfare would certainly draw the United States into the conflict and only strengthen the position of the allies leading to almost a certain defeat of Germany.

In addition to the Kaiser, The Imperial Chancellor, Bethmann Hollweg, who was undoubtedly the greatest opponent of using unrestricted submarine warfare and was very temperate on the use of the submarine arm in any fashion, would prove to be the proverbial long pole in the tent, throughout the entire debate, leading up to his eventual resignation. Hollweg was also supported in his views by Foreign Secretary von Jagow, who like the Kaiser and Chancellor believed such a strategy was too risky and would certainly antagonize the United States and other neutral countries to the point of entering the war.

The military figures of Imperial Germany were not exactly all in concert with their opinions at this time. There seemed to be disagreement over exactly how and in what manner (the ways and means) this new weapon should be utilized. However, as a collective group, they could agree that there was a sense that the U-boat would indeed play a key role. As John Terraine points out:

The German Admirals were discontented; they had the sense of holding a war-winning weapon in their hands, but not being allowed to use it properly. Yet the word itself required careful interpretation; the actual weapon was double-edged. On the one hand, the submarine enjoyed the priceless asset of invisibility, making it more difficult to counter than any naval craft previously built. On the other hand, there were certain things it could not do, or could not do in a traditional manner of naval warfare.

He is referring here to the German Prize rules which we will explore more closely later.

From the naval perspective, clearly Korvettenkapitan Herman Bauer, flag officer of the U-boat flotillas was the staunchest advocate and “the first to realize the deadly potential of using his boats in an all-out attack on British seaborne trade, with the object of starving the British Isles into submission.

A report of this strategy was submitted to the Chief of the German Naval Staff, Admiral von Pohl. As Tarrant points out, “Pohl vetoed the suggestion on the grounds that such a radical method of warfare would be a crude violation of international maritime law with regard to the method of destroying enemy merchant ships, to which Article 112 of German Naval Prize Regulations confronted.”9 Again, we will explore the concept of German Prize Regulations and international law later.

Admiral von Pohl would later go on to change his opinion in this matter, based on actions being taken at the time by the British and eventually become one of the leading advocates of a blockade of Britain.

A simple two-fold strategy was developed as a first step. First, place pressure upon Britain with a (submarine) blockade cutting off needed imports, and thereby through diplomatic negotiations, force the British to lift their own blockade against Germany. Second, by establishing this blockade zone, neutral shipping would be less likely to enter it in fear of being sunk and in tum decrease the risk of inadvertent attacks by German U-boats. Although this was not unrestricted submarine warfare, it was thought to be an effective way of challenging Britain without antagonizing the neutral states, most importantly the United States.

According to Gibson and Prendergast:

As a consequence of the decision to embark on the trade war, the late Admiral von Tirpitz, the Naval Secretary of State, gave an interview to an American Journalist, von Wiegand, hinting that a vigorous campaign against shipping by submarine might be started in the near future. By this balloon d’essai an attempt was made to ascertain American opinion on such a form of warfare. At the same lime, the Wiegand interview gave to Germany’s adversaries a warning of coming events.

Certainly this can be viewed as an effective public affairs strategy even by today’s standards. Its motives were to rally public opinion at home for the war effort, intimidate potential adversaries, and influence the public opinion of your enemy.

It is important to point out that these events are occurring in the early months of 1915, leading up to the first official proclamation that the territorial waters of the British Isles would be treated as a war zone. On February 4 1915, with approval from the Kaiser the following announcement was published:

1. The waters around Great Britain and Ireland, including the whole of the English Channel, are herewith declared to be in the War Zone. From February 18 onward, every merchant ship met with in this War Zone will be destroyed, nor will it always be possible to obviate the danger with which passengers and crew are thereby threatened.

2. Neutral ships, too, will run a risk in the War Zone, for in view of the misuse of neutral flags by the British Government on January 31, and owing to the hazards of Naval Warfare, it may not always be possible to prevent the attacks meant for hostile ships from being directed against neutral ships.

It would be 15 months before the Admiral Holtzendorff Memorandum advocating unrestricted submarine warfare based on two key factors would be accepted. The first was the continued arming of merchant ships and the binding limitations of prize rules, making U-boats extremely vulnerable. The second was based on the reported crop failure of 1916, which indicated a golden opportunity to deny needed food staples to the British public. If indeed the total effects of all out unrestricted submarine warfare could be levied prior to the 1917 harvest and provided the British would seek peace before the United States could fully mobilize, then Germany would achieve victory. Admiral Holtzendoff indicated that this could be accomplished within five months or prior to August I, 1917.

It is important at this point to discuss the issue of Prize rules, in particular Article 112 of the German Naval Prize Regulations. According to Tarrant, “a U-boat would have to surface, stop the intended victim, either by signal or a warning shot with its deck gun, send a boarding-party to the vessel to establish whether it belonged to a belligerent or neutral country, and, if it were of the enemy marine, make adequate provisions for the safety of the crew and passengers before sinking the vessel, either by gunfire, torpedo, or, as in the case ofGlitra scuttling.

I believe it safe to say that anyone could postulate why this practice would be extremely dangerous and not very well adhered to by U-boat Captains. Obviously this restriction was written from a historical perspective long before submarines had developed into a weapon of war. Add to this already dangerous situation, the fact that the British were now employing decoy techniques taking the form of merchant vessels equipped with hidden guns and one can begin to understand the obstacle facing U-boats and their commanders. These decoy vessels would become known as the British Q-ships. These Q-ships, heavily armed with hidden guns, were tasked with luring submarines in close, as prescribed in the prize hose rules, they certainly would be attacked and sunk by the heavily armed Q-ships. In essence bringing your boat into its most vulnerable position was clearly a non-starter for U-boat Captains and created a no win situation for U-boat.

Two other factors working to undermine the use of German U-boats as a legitimate weapon of war; first was the current practice of utilizing liners and in some suspected cases even hospital ships as troop transports and secondly it had been alleged that the British were in the practice of using neutral colors on their ships to avoid prosecution and attack from the German U-boat flotillas. These events led German leaders to issue as Gibson and Prendergast detail the following memorandum to submarine commanders.

The first consideration is the safety of the U-boat. Rising to the surface to examine a ship must be avoided for the boat’s safety, because, apart from the danger of a possible surprise attack by enemy ships, there is no guarantee that one is not dealing with an enemy ship even if she bears the distinguishing marks of a neutral. The fact that a steamer flies a neutral flag is no guarantee that it is actually a neutral vessel. Its destruction wilt therefore be justifiable unless other attendant circumstances indicate its neutrality.

Therefore even as strides were being made within the Gennan hierarchy to formalize a strategy for effective use of the submarine ann, world perception of that use left it far short of meeting the basic criteria of Jus in be/lo (conduct in war).

The final decisive point for the United States breaking diplomatic ties and eventually declaring war with Germany would come with the German declaration of unrestricted submarine warfare. To this point, tensions had existed between the two sovereign states, but there was still open dialog on the diplomatic level and even trade was being conducted between the two nations. For Germany, a half-hearted attempt at offering conditions for peace in December 1917, which it could be argued was nothing more than a diplomatic precursor to the following declaration of unrestricted warfare, the die was cast.

For their part, the Americans had truly remained neutral. They even went as far as on occasions cautioning the British about their method of blockade of Germany and the fact that their policy of including food stuffs as a classification of contraband, thereby making such cargo open to seizure, was border line. America’s view of this practice was that Britain was in essence starving Germany and in so doing was directly impacting the German non-combatant populous. A practice that would not easily pass the jus in be/lo criteria in itself. In a sense Britain was doing exactly what they were accusing the German military of doing conducting a war on non-combatants.

As President Wilson took his war message to Congress he outlined the conduct of Germany and its unrestricted warfare as a motivating factor for America’s cessation of diplomatic relations and war declaration. President Wilson would state:

On the 3rd of February last I officially laid before you the extraordinary announcement of the Imperial German Government, that on and after the I” day of February it was its purpose to put aside all restraints of law or of humanity and use its submarines to sink every vessel that sought to approach either the ports of Great Britain and Ireland or the western coasts of Europe or any of the ports co11trolled by the enemies of Germany within the Mediterranean. That had seemed to be the object of the German submarine warfare earlier in the war, but since April of last year the Imperial Government had somewhat restrained the commanders of its 1111dersea craft, in conformity with its promise, then given to us, that passenger boats should not be sunk, and that due to warning would be given to all other vessels which its submarines might seek to destroy, when no resistance was offered or escape attempted, and care taken that their crews were given at least a fair chance to save their lives in their open boats. The precautions taken were meager and haphazard enough, as was proved in distressing instance after instance in the progress of the cruel and unmanly business, but a certain degree of restraint was observed. The new policy has swept every restriction aside.

Jn conclusion, “German submarines up until November I J, 1918 /tad accounted for the sinking of 2,677 British merchant and fishing vessels. eq11ali11g a gross tonnage of 6,692,642 tons and causing loss of life to some 12,821 souls. “15 These statistics are only reflective of British losses during this period.

Clearly the juxtaposition for Germany was between utilizing a weapon that could potentially bring the war to an end and with it peace; or utilizing a weapon in a manner that would render it totally destructive in nature, would very likely bring other neutral nations including the United States into the war as an ally to Great Britain and leave Germany with the disdain from the entire world community.

The internal debate surrounding this very issue conducted by the military and political leadership in Germany, ebbed and flowed over a four year period, and only further demonstrated that this decision was one that had extremely significant consequences. These consequences would eventually seal Germany’s fate and forever shape the history of the world. Clearly throughout the period 1914 to 1917, it was a topic that continued to elude a definitive strategy. When a final decision was actually made, it was most likely too late to effectively influence the outcome of the war. Likewise, it had given the Allies an opportunity to develop a counter strategy.

In my opinion, Charles Townsend summed it up very succinctly in his introduction to The Oxford History of Modem War:

The entire war making capacity of societies became a legitimate military target. Hence the British imposed a naval blockade of Germany-a traditional British mode of operation, but now more crushing than ever in the past through a mixture of geographical accident and technical development. Within a year Germany was visibly beginning to starve to death, and i11 the last wimer of the war nearly three¬∑quarters of a million Germans were to die of hunger. Germany’s response was catastrophic. Possessing a wholly new technology in the form of the submarine, Germany could not exploit it without breaking international law (a law which as John Hattendorf shows had been substantially defined by Britain). The decision to declare unrestricted submarine warfare which brought the USA into the war, was not taken without long eliberation. In rational term, it was probably an impossible decision to make, beca11se statistical calculations on which it had to be based were more or less hypothetical. B11t, in the end, the prevailing arg11ment was visceral rather than rational. Germany gambled not just to avoid defeat, but to win a decisive victory which would enable it to dictate the terms of peace.

For Germany, the issue of deciding on a strategy of unrestricted submarine warfare must be placed in proper context. One needs to ask what the ultimate ends were for German leadership at the time. Was it to end the blockade of Germany? Or, was it to bring the war to a close-on ones terms? In either event, it would be difficult to argue that whatever ways and means are available should be used. However, that decision should be decisive and not one that is hampered by apprehension and self-imposed limitations. Certainly, it can be said that rules and/or laws are only effective if they are followed by all parties concerned. It could also be reasonably argued that although from a diplomatic standpoint unrestricted submarine warfare as a strategy was not officially sanctioned until 1917, from a tactical standpoint it was occurring long before.

Possession of a new unproven weapon, as would again be witnessed in WWII-with the atomic bomb, undoubtedly leaves leadership with an ethical dilemma that can not be easily or necessarily rationally decided. If we follow a Darwinian way of thinking in war, then the rules certainly become less important and victory and survival become the bottom line. In the future, we can only pray that world leaders will have the wherewithal and common sense to use new weapons and technology in a responsible manner.

Author’s Note: It is very ironic that tire unrestricted submarine warfare that brought the U.S. into WWI, would become a key strategy for the U.S. in the Pacific during WWII. Thank you to Dr. Bernard Fine/ for his guidance and advice d11ring the preparation of this paper.

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