Military theory is a way of distilling the raw materials of history into a concentrated, potent form that educates the strategist and commander. In this way, theory can serve as a starting point for strategy. By examining ways in which the theories of Carl von Clausewitz and Giulio Douhet affected strategies, warfighting, and outcomes, the would-be strategist can observe both the benefits and limits of military theory. Conversely, there have been historical episodes in which theory held little sway on strategy. Such a counterexample may further illuminate theory’s role in strategy development, for good or ill. While sound military theory is a good starting point for strategy, context and execution matter. The positive impacts of theory upon strategy are often limited by the context in which theoretical principles are applied, and by the commander’s judgment and skill in applying them.
Modern strategic theorist Professor Colin Gray believes theory is more than a mere starting point. Theory, he says, “moves the course of history…enables us to make decisions rationally…[and] yields meaning to our world.” Statecraft and war, he continues, “rest inalienably upon theory.” Gray has in mind Clausewitz’s archetypal On War—a dense tome quoted by many but understood by few, which aimed at the sweeping impact Gray describes. It is also a book that Clausewitz admitted in its unrevised form constituted “a formless mass.” Despite its density and formlessness, generations of strategists and commanders have attempted to apply On War to strategy, with varying degrees of success.
Clausewitz, Bismarck, and von Moltke
Not surprisingly, Clausewitz’s intellectual and cultural heirs, Chancellor Otto von Bismarck and Field Marshal Helmuth von Moltke, translated his principles into successful strategy. Their judicious application of theoretical principles to real-world strategy provides perhaps the most convincing fulfillment of Gray’s demands of military theory--that it enable decision-makers to act rationally, thereby move the course of history in the direction of their own interests. Yet their success owes much to a favorable confluence of theory, culture, and context.
“No statesman ever adjusted war to policy with a nicer judgment than Bismarck.”
Clausewitz argues that war is not a departure from politics but “the continuation of policy by other means,” and that therefore, “wars must vary with the nature of their motives and of the situations which give rise to them.” War cannot be separated from political purpose and constraints. As products of the very Prussian military education system and state that Clausewitz helped create in the first few decades of the 1800s, Bismarck and von Moltke shared a deep textual and cultural understanding of On War. They employed his theory in the Wars of German Unification (1864 to 1871), judiciously applying violent means to achieve political and territorial ends, with lasting strategic impact. Praising Bismarck in overtly Clausewitzian terms, Sir Halford Mackinder asserts, “No statesman ever adjusted war to policy with a nicer judgment than Bismarck.” Mackinder, an original authority on geopolitics, points out that each of Bismarck’s three short wars concluded with treaties favorable to Prussia, leading directly to a unified Germany. In accordance with Clausewitz’s theory, Bismarck managed von Moltke’s military victories (means) to pursue the greater political strategy of unification (ends).
Bismarck and von Moltke owe much of their success to their understanding of another Clausewitzian principle: that harmony of purpose must exist between statesman and general. Clausewitz says that “the first, the supreme, the most far-reaching act of judgment that the statesman and commander have to make is to establish…the kind of war on which they are embarking, neither mistaking it for, nor trying to turn it into, something that is alien to its nature.” Bismarck and von Moltke harmonized their efforts while limiting the scope of each war so as not to exhaust Prussia’s resources or ignite greater conflicts. In accordance with this fundamental principle of On War, both Bismarck, the strategist-statesman, and von Moltke, the strategist-commander, effectively calibrated the purpose and scope of their wars to the state’s political climate and available resources. Von Moltke and Bismarck applied Clausewitz’s theory with intellectual understanding and seasoned judgment, significantly advancing Prussia’s power and interests. Later Germans read Clausewitz narrowly or misinterpreted him, forging less successful strategies as a result.
Clausewitz and Hitler
A later generation of Germans in Hitler’s Third Reich attempted to apply Clausewitz in name only, without truly understanding the theory. Clausewitz translator and historian Peter Paret writes that Clausewitz’s impact on various strategies and wars has been “difficult to discern and even harder to verify.” Specifically, there is some debate about how Clausewitz’s principles affected the Third Reich. From historian Peter Baldwin’s article, “Clausewitz in Nazi Germany,” one can draw three relevant conclusions. First, elements of Clausewitzian thought infused the militaristic Nazi culture, owing to Clausewitz’s institutional contributions as a sort of founding father of the modern Prussian military. Second, Hitler quoted and referenced Clausewitz more than nearly any other intellectual influence. Yet Hitler’s overt references must be qualified by the third, and perhaps most important conclusion: Clausewitz qua Clausewitz was rarely present in Nazi strategy. Paradoxically, he was the least present in his true form when he was explicitly referenced. Instead, a deranged, irrational Nazi strategy draped itself in a cape of legitimate theory, applying Clausewitzian phrases without regard for context or good judgment.
Instead of adjusting war to realistic political objectives and constraints, as Bismarck and von Moltke had done, Hitler misappropriated Clausewitz’s references to absolute war and maximum force, using them out of context to justify his all-or-nothing strategy for German hegemony. Clausewitz had begun On War with Montesquieu’s political treatise The Spirit of the Laws in mind. On War was to be a work of philosophy and theory, not a practical manual like the work of his peer Antoine-Henri Jomini. When Clausewitz discussed total war as war’s “ideal form,” he meant it in a philosophical sense—the “extremes” in scale and passion of Napoleonic warfare, which he had witnessed first hand, carried to their logical conclusion. In his dialectical fashion, Clausewitz makes the theoretical function of “absolute war” clear by describing the political and physical limitations that keep such a war from occurring. He further underscores this point by warning statesmen and generals to make war with full awareness of these practical limitations.
...victory leads easily to overextension, which leads to defeat.
Hitler, of course, defied these limitations, to the detriment of his strategy and overall war effort. The limitations of resources, the soldiers’ will, and political will are all bound up in Clausewitz’s culminating point. Every operation and war will reach a point where the maximum realistic gains have been made within a state’s capabilities and will. The culmination point illustrates that “every attack loses impetus as it progresses,” both in the physical and moral sense. Once Bismarck had united Germany, he stopped waging wars. This decision reflects Bismarck’s awareness of the culmination point, as well as his alignment of war’s means with his rational political ends. Passing Clausewitz’s test for strategic success, he “achieved great result with limited means.” Hitler, on the other hand, admitted no knowledge of the culmination point, and therefore expended unlimited means, only to achieve disastrous results. Strategic consultant Edward Luttwak therefore uses Hitler to exemplify a principle he derived from Clausewitz’s culmination point: victory leads easily to overextension, which leads to defeat.
In concluding “Clausewitz in Nazi Germany,” Baldwin states: “Those who had power did not learn from Clausewitz, but sewed his name like a fashionable label into their pirated, imitative intellectual vestments.” The Nazis perverted the normal function of sound theory as a starting point for strategy, instead wrapping a doomed strategy in stolen threads of a theory they failed to comprehend. Had they employed Clausewitz with better understanding of the theory itself and better judgment in application, their strategy may have benefitted greatly. Let us be grateful for their error.
Douhet and the RAF
Departing from this case of implicit influence and misappropriation, it may be valuable to examine a case in which a military theory was explicitly and deliberately used as a starting point for strategy. In doing so, it may further benefit us to take J.C. Slessor’s advice, “thinking wider and using larger maps” than the map of central Europe to which we have so far been earthbound. Historian Michael Howard provides a neatly-packaged example: the British Royal Air Force explicitly and deliberately employed Giulio Douhet’s early airpower theory in its strategy and preparations for World War II.
Douhet’s book Command of the Air argued that future wars would be primarily fought by aircraft. Specifically, he envisioned unstoppable bombers from the belligerent states rapidly laying waste to opponents’ aerodromes, industries, and major cities with incendiary and chemical bombs. This vision of future warfare took hold in policy circles and popular culture in the 1920s and 1930s, leading Britain to build a strategy and an independent air force premised on strategic bombing as a rapid war-winning instrument in its own right. However, a failure to account for contextual factors of technology undermined Douhet’s theory and the ensuing RAF strategy. It was popularly believed that “the bomber would always get through.” In fact, technological advances in radar, electronic warfare, and interceptor aircraft, combined with RAF bombers’ limited payloads and poor accuracy, led to an aerial war of attrition. The bomber force’s heavy losses throughout the war and the technological cycle of measure-countermeasure made strategic bombing more difficult, and far less effective, than it had been in theory.
Douhet’s theory remained a good starting point for strategy. He had correctly anticipated the critical role of aerial bombardment in modern war, and as bombers and later missiles overcame many of the technological limitations and countermeasures described above, his work would gain new renown in the missile age. In the meantime, however, the RAF (with the help of the U.S. Army Air Forces) had to compensate for limitations of theory and strategy with strength and will in execution. Instead of the rapid, decisive exchange Douhet had envisioned, the allied bomber forces endured years of deadly, brute-force battle, only securing a Douhetian “command of the air” in the last two years of the war. It credits the will of their leaders and commanders, and even more so the courage of the crews themselves, that the bomber offensive did eventually contribute to the destruction of the opposing force and overall victory.
Finally, if we consider Luttwak’s observation that the realm of military theory and strategy “is pervaded by a paradoxical logic,” perhaps we can learn something useful about theory’s relationship to strategy by observing a strategy crafted and employed without the benefit of theory. Everett Dolman states that no sense can be made of the world without theory. Dr. Harold Winton, however, argues against this position in his analysis of Civil War general Ulysses S. Grant. Sense can be made of the world, and of war, without theory. For Grant, to do so required courage and superior resources. From these two, Grant derived the ability to take bold risks, survive, and adapt, even if some risks led to tactical defeats. Essentially, where sound theory might have provided a starting point for a more efficient campaign, Grant substituted boldness and superior resources, and learned the rest on the job.
Grant lacked the benefits of theory. Military strategy and theory had not figured significantly in his education at West Point, which maintained an engineering focus at the time. Nor did Grant engage in “serious professional reading” during his career. Nevertheless, between 1861 and 1863, Grant amassed a series of significant victories from Fort Donelson, to Shiloh, to Vicksburg, and thereby gained the trust of his commander in chief. It follows that his successful strategy must have resulted from understanding of context, and his superior judgment. In fact, Winton does indeed highlight Grant’s “intense powers of observation and reflection,” along with his calm demeanor, successful delegation, and use of reserves—in essence, his perception and judgment. Meanwhile, historian Arthur Conger emphasizes that Grant brought the full might of Union resources to bear on the Confederacy—a strategy with deep contextual understanding, divined during execution, that J.F.C. Fuller elevates to visionary significance. At this point, a would-be strategist might be tempted to avoid theory altogether, hoping that he, like Grant, can depend upon his own natural genius. To that reader, the following should be explained: not only did Grant perceive his circumstances accurately, but those circumstances heavily favored him versus his Confederate opponents.
Grant enjoyed the complete political and material support of his political master Abraham Lincoln, who constrained him only to seek out and do battle with the enemy. Therefore, his courage, self-confidence, and natural genius were free to roam and create on the battlefield, “in liberty of bloody hand…with conscience wide as hell.” Focused solely on military victory, Grant’s strategy was whatever emerged; even von Moltke would have envied such simple purpose and operational freedom. Due to these contextual elements, and his good fortune in surviving many battles, he had the luxury of learning on the job, formulating strategy as his campaign progressed. In short, the specific context that enabled Grant to succeed without a sound theoretical foundation was rare. It is possible to achieve a sound strategy without theory, but it is not likely, especially in today’s uncertain and complex political environments. While Grant is an interesting case, he provides a poor example for contemporary practitioners.
A Metaphor, and Conclusion
Dolman describes theory as “the filter through which our mind perceives the world, through which it organizes thought.” His image of a filter, which restricts the flow of fluid and removes particles from a suspension, is ironic given his view of strategy, which he says should always aim to broaden perspectives and increase options. How is one to craft an ever-expanding strategy using a tool that restricts and removes? I prefer the more comprehensive metaphor of an old-fashioned pot still. This metaphor illustrates the value of theory as expressed by J.F.C. Fuller. Without distillation, you have only a large mash of ingredients in a giant pot—the raw data of history. But we don’t want mash. We want whiskey.
As Fuller put it, “We want truth. We require not merely a chronology of past events, but means of analyzing their tendencies.” The process of historical study and reflection stresses and condenses the historical mash, drawing out potent, essential elements. These elements are collected as theoretical principles, ideally potent and simple—akin to the clear, extremely high-proof output of the still. The process is not finished; the powerful, difficult-to-digest theory should be barreled in context, then aged and systematically tested before finally it can be packaged, at the right time, by people with who understand it—into strategy. This metaphor illustrates the essential role of theory as described by Clausewitz: theory is “an analytical investigation leading to a close acquaintance with the subject; applied to experience, in our case, to military history—it leads to a thorough familiarity with it.”
Without distillation, you have only a large mash of ingredients in a giant pot—the raw data of history. But we don’t want mash. We want whiskey.
Gray says that theory enables us to make decisions rationally; I would say that theory constitutes a set of assumptions, based on history, that may enable strategists and commanders to make decisions rationally, if applied judiciously, in context. Mine is a highly-couched argument, and intentionally so; this is the reason that theory can be no more than a starting point. If applied with thorough familiarity and good judgment, as Bismarck and von Moltke applied Clausewitz, then military theory is an excellent starting point, which leads to a successful strategy and a beneficial military effort. If applied with a limited or selective reading, absent of reflection, or in poor relation to context, military theory can contribute to a deeply flawed strategy. Theory’s ability to educate the strategist therefore depends on the potential and will of the strategist to be educated—a theorem which touches upon the subject of military genius, a subject for discussion in another chapter…or over a glass of whiskey.
Michael Trimble is an officer in the US Air Force and a student at the School of Advanced Air and Space Studies at Maxwell Air Force Base, AL. He has served in multiple assignments and operational deployments as an instructor pilot in the C-130J Super Hercules. The conclusions and opinions expressed in this article are his alone and do not reflect the official position of the U.S. Air Force, the Department of Defense, or the U.S. Government.
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Header Image: "17th Lancers Advancing into Battle" by David Cartwright (National Army Museum)
 Colin S. Gray, The Strategy Bridge: Theory for Practice (Oxford, UK: Oxford University Press, 2010), 8.
 Gray, Strategy Bridge, 8.
 Carl von Clausewitz, On War, ed. and trans. Michael Howard and Peter Paret (Princeton, NJ: Princeton University Press, 1976), 69.
 Halford J. Mackinder, Democratic Ideals and Reality (1919; repr., Washington, DC: National Defense University Press, 1996), 13.
 Clausewitz, On War, 87-88.
 Mackinder, Democratic Ideals and Reality, 13.
 Clausewitz, On War, 143.
 Clausewitz, On War, 88.
 Peter Paret, “Clausewitz,” in Makers of Modern Strategy: from Machiavelli to the Nuclear Age (Princeton, NJ: Princeton University Press, 1986), 213.
 P.M. Baldwin, "Clausewitz in Nazi Germany," Journal of Contemporary History 16, no. 1 (1981): 5-26.
 Baldwin, “Clausewitz in Nazi Germany,” 10.
 Baldwin, “Clausewitz in Nazi Germany,” 11.
 Baldwin, “Clausewitz in Nazi Germany,” 18.
 Clausewitz, On War, 605; and, Baldwin, “Clausewitz in Nazi Germany,” 13-15.
 Paret, “Clausewitz,” 187-188.
 Clausewitz, On War, 75-77
 Clausewitz, On War, 78-85.
 Clausewitz, On War, 528, 566-573.
 Clausewitz, On War, 528, 566-573.
 Clausewitz, On War, 71, 528.
 Mackinder, Democratic Ideals, 13.
 Clausewitz, On War, 573.
 Edward N. Luttwak, Strategy: The Logic of War and Peace (Cambridge, MA: Harvard University Press, 2001), 80-81.
 Baldwin, “Clausewitz in Nazi Germany,” 22.
 J.C. Slessor, Air Power and Armies (1936; repr., Tuscaloosa, AL: University of Alabama Press, 2009), 204.
 Giulio Douhet, The Command of the Air, trans. Dino Ferrari (1942; new imprint, Washington, DC: Office of Air Force History, 1983), 28-29, 128-129.
 Douhet, Command of the Air, 10, 23-25, 34-35, 55.
 Michael Howard, War in European History, 2nd ed. (Oxford, UK: Oxford University Press, 2009), 129.
 Howard, War in European History, 129-130; and, Luttwak, Strategy, 89-90 (on the “vertical” effect of technology on strategy).
 Howard, War in European History, 130.
 Luttwak, Strategy, 27-28.
 Bernard Brodie, Strategy in the Missile Age, new RAND ed. (Santa Monica, CA: RAND Corporation, 2007), 402.
 Howard, War in European History, 130.
 Luttwak, Strategy, 2.
 Everett Carl Dolman, Pure Strategy: Power and Principle in the Space and Information Age 2nd ed. (London, UK: Routledge, 2011), 12.
 Harold R. Winton, “An Imperfect Jewel: Military Theory and the Military Profession,” Journal of Strategic Studies 34, no. 6, (2011): 866-870.
 Winton, “Imperfect Jewel,” 866-867.
 Eliot Cohen, Supreme Command: Soldiers, Statesmen, and Leadership in Wartime (New York, NY: Anchor Books, 2002), 43-45.
 Winton, “Imperfect Jewel,” 870.
 Winton, “Imperfect Jewel,” 869.
 Clausewitz, On War, 89; and, Abraham Lincoln, letter to Grant, 30 April 1864, in Cohen, Supreme Command, 15.
 Clausewitz, On War, 86, 89, 101, 112; and, William Shakespeare, The Life of King Henry V, Act 3, Scene 3.
 Dolman, Pure Strategy, 20.
 Dolman, Pure Strategy, 12.
 Dolman, Pure Strategy, 9, 12, 18.
 Col J.F.C. Fuller, The Foundations of the Science of War (1926; repr., Fort Leavenworth, KS: US Army Command and General Staff College Press, 1993), 21.
 Clausewitz, On War, 141.
 Gray, Strategy Bridge, 8