Dr. John T. Kuehn is Associate Professor of Military History and Curriculum Developer in the Department of Military History at the U.S. Army Command and General Staff College.
German submarine warfare from 1915 to 1918 was the global terrorism of its day. Submarines attacked targets widely regarded as "innocent" and were extremely effective at it. In that respect, the U-boat campaign during World War I is strikingly similar to the terrorist insurgencies of today, especially those using suicide and improvised explosive device (IED) bombing tactics. Whether the bombs and guns are going off in Bali, Mumbai, Peshawar, Kabul, or Mosul, they are all attacking innocents for military purposes like the "illegal," unrestricted U-boat "wolves" of a recent but forgotten age. Such tactics—whether suicide bombers or submarines—have invariably been those of weaker groups turning to a despised form of war in desperation. Even Mao Tse-tung, among the more articulate theorists of insurgent warfare, referred to guerrilla and irregular methods as weaker and advised proceeding to the "higher" forms of war for a final decision.1
U-boats—The Terror Weapon
There is more to be learned from the analogy between U-boats and terrorist bombing than their commonality of method. For example, consider the sheer tension and frustration indicated by the Ambassador to the United States in historian John Terraine's account of the impact of German submarines on the British psyche in 1917:
At the present rate of destruction more than four million tons will be sunk before the summer is gone. Such is this dire submarine danger. The English thought that they controlled the sea. . . . The submarine is the most formidable thing the war has produced—by far—and it gives the German the only earthly chance he has to win.2
One can imagine any Israeli, American, Pakistani, Iraqi, or other government making a similar statement about terrorist methods: "It gives the terrorist/insurgent the only earthly chance he has to win."
Returning to 1917, these views were not limited to the British. The Russians, Italians, and French raised similar cries. President Woodrow Wilson became so alarmed about the German terror offensive against the sea lines of communication that he sent Herbert Hoover, a bright, number-crunching expert, to Europe to investigate the U-boat's real impact on his new allies. Was the damage simply British propaganda? Hoover reported that bread riots were imminent if the carnage continued, not so much in Great Britain as in Italy and France. The Germans had not only sunk record numbers of ships; they had sunk almost the entirety of the South American grain harvest bound for Europe.3
What happened that allowed the Allies to prevail? First, one must back up and understand that the Allies had adopted a ruinous strategy for combating the U-boat. This strategy was based on a long and comfortable naval tradition that esteemed the offensive, kinetic form of warfare that had characterized naval combat for millennia. The British, faced with the resumption of German U-boat warfare in February 1917, continued to employ the supposedly effective tactic of patrolling the sea lanes "hunting" for U-boats in the finest tradition of the Royal Navy. After all, commerce warfare, or guerre de course, had never really succeeded against a major modern naval power. Never before had the commerce raiders been able to achieve a decisive result in a sustained campaign of privateering and raiding against sea lines of communications. Alfred Thayer Mahan's histories were full of examples to support this position, and if that wasn't enough, so were those of Sir Julian Corbett, the great British naval theorist, at least until the German submarines began to reap their horrible harvest.4
When the Germans resumed unrestricted submarine warfare against the Allies, an incredible crap shoot in hindsight, they had done something the British had not—they had looked at the lessons learned during the first go at unrestricted methods in 1915 and made crucial adjustments to become more effective should they decide to try it again. They prepared new, smaller UB-class boats that were prefabricated and easily assembled to operate out of a new base in Bruges, Belgium. This conferred the factor of strategic surprise for the Germans, since to that point U-boat sorties by the High Seas Fleet had been limited to their small coastline between the Netherlands and Denmark. Additionally, the Germans built reinforced concrete submarine pens in anticipation of an Allied naval counterattack on the source of the scourge. Finally, German improvements to their torpedoes came of age in 1917. Significantly, 1916 saw the greatest production of U-boats during the war.5 These measures, combined with the ferocity and surprise of their attack, came close to being the sort of "shock and awe" that modern-day, effects-based operations devotees dream of. Nonetheless, the British already knew they had a serious problem in late 1916 with the barely more restrained "restricted" U-boat campaign. These restrained methods, moreover, had already led to over 355,000 tons of lost Allied shipping in December 1916. What makes all of this more amazing is how ill prepared the British were for the all-out campaign in February 1917. An air of hopelessness was reflected in the words of Colonel Charles á Court Repington: "It was at present a question whether our armies could win the war before our navies lost it."6 Nonetheless, under Admiral Sir John Jellicoe's direction, the Royal Navy had instituted—at the last minute, one might say—a long-overdue organizational response to the problem with the establishment of the Admiralty Anti-Submarine Division under Admiral A.L. Duff.7
Setting up an antisubmarine warfare (ASW) syndicate is one thing; adopting the correct antisubmarine measures is entirely another. The challenge was unprecedented; as John Terraine wryly noted, "There was no manual" for ASW. So the Royal Navy essentially adopted the policy already in place for commerce raiding, the use of frigate-type vessels to counter the U-boat. Here is where hidebound tradition and perhaps the "Spirit of Nelson" may have proved most unfortunate. Although the Royal Navy had a useful warship type, the destroyer, ready at hand for this job, it had far too few of them. A general shortage of destroyers bedeviled all the major navies throughout the war. Destroyers were originally torpedo boat destroyers intended to screen the main bodies of fleets against torpedo attack, itself a rather new development in warfare. There were precious few of them left after their assignment to the main fleet duties and troop convoys. The British attempted to build more, but that only became a priority at the eleventh hour. Ironically, the Germans also helped provide the solution for this shortage when they caused the United States to enter the war.8
In the area of antisubmarine weapons, the British learned that gunfire scored few kills on the rare occasions when U-boats were caught on the surface. The Germans could dive faster than the British could man their guns, never mind bracket their targets, especially at night. In response, the British developed the first generation of depth charges, but like most new weapons systems they were ineffective at first. A means had to be devised to shoot them far enough from the ship so that the hunter would not be damaged or killed along with the prey. It was only in 1917 that a "pistol" was introduced along with variable depth settings for the Type-D depth charges. As with the destroyers, depth charge stocks were abysmally low when the Germans unleashed their terror campaign. However, none of that mattered if the wrong operational approach to the problem was taken—and it was. The British, in a phenomenal misunderstanding of the statistics of this type of warfare, decided not to convoy ships, in part because they did not have enough escorts. Nonetheless, the mathematics dictating that more ships would get through in convoys escaped the minds of officers schooled in commerce raider hunting. One U-boat might meet one merchant ship and sink it. One U-boat meeting a convoy would at best sink one ship, and the others would all get away—guaranteed.9
The other key problem was how to locate the submarines other than going to the site of a burning merchant ship ("flaming datum" in ASW-speak), or more often the last presumed location. There were also hydrophones, but these were crude, only useful at extremely short ranges, and subject to interference by the ambient noise of anything with a screw in the water. Thus, the chances of successfully making contact with submarines in such open-ocean patrolling, even in areas of known danger, were ridiculously low. And so it was that the exactly wrong approach of hunting the U-boats was employed instead of using the small numbers of destroyers as escorts.10
The results were catastrophic. Not only did the Germans meet their tonnage goals, they exceeded them. As noted, they had already managed to sink the South American grain harvest for 1916–1917. The risk they took concerning American entry into the war seemed to pay off, especially when President Wilson balked at going to Congress for an outright declaration of war after the unrestricted submarine campaign began. It was only the notorious telegram by Foreign Minister Arthur Zimmermann in late February urging Mexico to declare war on the United States, decoded and provided by a desperate British government, that prodded Washington into participation. Even then, as historian Barbara Tuchman notes, only the German Foreign Minister's incredible admission of the telegram's authenticity rallied American public opinion in favor of war prior to the President's decision.11
As it turned out, Washington's response was almost too late. The American declaration of war in April 1917 came during the worst months of the U-boat terror campaign. This need not have happened. The antisubmarine division of the Admiralty had all the analytic data at its fingertips to indicate the wisdom of convoying. As early as February, Duff and his staff were arguing that the data suggested that the escorted convoy was the best means to counter the U-boat, given the low losses in that formation.12 However, there were strong interests opposed to the convoy, and the strongest argument seemed to be that there simply were not enough escorts. All of these arguments proved to be flawed, but the issue of escorts was in part solved by the entry of the Americans and about 30 destroyers into the calculations for the needed escorts. Some have even argued that these ships provided the necessary margin for the tentative adoption of the convoy system as an experiment, almost a last gasp. Offensive patrols continued. But the results of convoying were immediate. Indeed, John Terraine argues that the "convoy acted like a spell" in turning the naval war in the Allies' favor. The tonnage of ships went down slowly through the summer, and then plunged drastically in the fall. The Germans were forced to shift their patrol areas. By the end of the year, although much hard convoying remained, the Germans could see the writing on the wall.13
What happened? The Allied navies had regained the initiative and the ability to move what they needed to sustain the war effort by sea. Their key vulnerability was also their key strength. The Germans had to come to the convoys in the open ocean to be successful. Even without escorts, the sheer math of the convoys resulted in lower loss rates. Once ships were escorted, the U-boats became the hunted and not the hunter. The addition of aircraft patrols further hindered the U-boats because finding where they were not was as important as finding where they were. Denied their prey, the U-boats had to attack the convoys—a no-win situation in 1917 and 1918 once the escorts, weapons, and tactics were in place.
Afghanistan as an Ocean
How does the submarine experience relate to terrorism, or more specifically to the insurgent war in Afghanistan with the Afghan Taliban and their Islamic foreign fighter allies? In important ways, the North Atlantic Treaty Organization (NATO) strategy in Afghanistan has mirrored the approach of the Royal Navy to the U-boat menace. Like the Royal Navy, NATO forces in Afghanistan have used tactics principally focused on hunting and killing the insurgents (mostly Taliban). Focusing on the population was not the "main effort," as discussed in some recent heartrending memoirs such as Craig Mullaney's The Unforgiving Minute.14
The International Security Assistance Force (ISAF) in Afghanistan adopted a more mixed approach as the focus shifted from Iraq to Afghanistan in 2008, again like the Royal Navy in 1917. The doctrine around which these operations were built is found in Field Manual (FM) 3–24/Marine Corps Warfighting Publication 3–33.5, Counterinsurgency, which was spearheaded by then–Lieutenant General David Petraeus while he was Commandant of the Army Command and General Staff College at Fort Leavenworth. This doctrine has sometimes been called "populationcentric" counterinsurgency. It is potentially a resource-intensive approach that relies on a relatively large troop-to-population ratio for success—as many as 25 counterinsurgent troops per 1,000 residents. It also requires a substantial time commitment.15 FM 3–24 methods were employed more and more, but in concert with kinetic methods under General David McKiernan—not due to tactical or operational preference so much as to expediency, given the limited numbers of troops. In fact, the kinetic side of this approach may have done more harm than good and been a factor in McKiernan's eventual relief.16
The population of Afghanistan can in some measure be compared to the merchant ships in World War I, each needing escort. Thus, there is the constant demand for more troops in Afghanistan. Troops equate to escorts, and again there are not enough. How does one regain the initiative if he cannot completely "convoy" by concentrating the entire population in order to protect it? After all, the lower force ratios will in all likelihood continue. Even 40,000 more Americans is only a "drop in the ocean" that is Afghanistan. Is there no way around this conundrum? Certainly the British method during the Boer War, using concentration camps, is to be avoided. In any case, the British were not out to win over the population to a new indigenous political construct in the manner of NATO and the United States in Afghanistan.17
The example of the anti–U-boat campaign suggests a modified "convoy" approach. Something along these lines has already been suggested by a number of writers who know the area well.18 What it boils down to is finding the closest analog to "convoys" that Afghanistan's demographics and geography permit, prioritizing and then providing the security (escorts) that will force the enemy to react to NATO's campaign design.19 It is a modified population-centric approach that, like convoying, will require time and resources. NATO needs to match existing sustainable force levels to the most urbanized areas of the country and to logistic support. For example, such major cities as Kabul, Khost, Kandahar, and Herat might become "enclaves" (convoys) wherein priority one is security. The Taliban and their foreign fighter allies would have to come to NATO and the Afghan security forces.
This would entail retrenchment, and some might say abandonment, of large swaths of ground. But as a Pakistani major has recently argued, it offers some chance of long-term success in concert with other political measures. In fact, the major compares the problem in Afghanistan to "arrest[ing] the sea."20 The Taliban has a poor record of sustained popular satisfaction with their governance—although they do know how to govern locally, if repressively. The Afghans in general have a demonstrated record of infighting when there are no foreigners to coalesce against.21 These attributes can be viewed as strengths that decrease the enemy's initiative and undermine his base of support once the basis for unity is withdrawn.
4 Terraine, 19; Alfred Thayer Mahan, Naval Strategy (Washington, DC: U.S. Government Printing Office reprint, 1991), 109, and Sir Julian Corbett, Some Principles of Maritime Strategy (Annapolis: Naval Institute Press reprint, 1988), 176, 310–312.
5 Terraine, 17–21.
6 Cited in Terraine, 22–23.
7 Ibid., 24.
8 Ibid., 48–49.
9 Ibid., 46. Terraine writes, ". . . it was the submarine war, above all, that gave April, 1917 the quality of terror."
10 Ibid., 28–34.
11 Barbara Tuchman, The Zimmermann Telegram (New York: Viking Books, 1958), 176–178.
12 Paul W. Halpern, A Naval History of World War I (Annapolis: Naval Institute Press, 1995); see also Terraine, 53–54.
13 Halpern, 355–368; Terraine, 57; and Dennis Conrad, "Were They Really So Unprepared? Josephus Daniels and the U.S. Navy's Entry into World War I," unpublished paper, September 11, 2009.
14 Craig M. Mullaney, The Unforgiving Minute: A Soldier's Education (New York: The Penguin Press, 2009), 362.
15 FM 3–24, 1–13 and passim. For a populationcentric critique as well as the issue of initiative, see Gian P. Gentile, "Gaining the Initiative in Afghanistan," available at .
16 See Small Wars Journal Blog, especially
17 Thomas Packenham, The Boer War (New York: Random House, 1979), especially chapters 36–38.
18 Mehar Omar Khan, "Don't Try to Arrest the Sea: An Alternative Approach for Afghanistan," available at
19 Gentile. See this article for the importance of an approach that shifts the initiative to NATO.