Carl von Clausewitz's On War E-Book

Hew Strachan

• Herausgeber: Atlantic Books
• Kategorie: Geisteswissenschaft
• Serie: BOOKS THAT SHOOK THE WORLD
• Sprache: Englisch

Seitenzahl: 316

Veröffentlichungsjahr: 2013

Beschreibung

On War by Carl von Clausewitz was first published in Germany after the Napoleonic Wars. One of the most significant treatises on military strategy ever written, it is still prescribed at various military academies today. Its description of 'absolute war' and its insistence on the centrality of battle to war have been blamed for the level of destruction involved in both the First and Second World Wars. Hew Strachan's accessible book challenges the popular misconceptions that surround On War. He dispels the notion that for Clausewitz policy necessarily shapes war, asserting instead that war has its own dynamic and that its reciprocal effects can themselves shape policy. Strachan returns to the very heart of On War to recover the arguments at its core; in the process challenging the received wisdom about this cornerstone of military strategy.

Leseprobe

Other titles in the Books That Shook the World series:Available now:

The Bible by Karen Armstrong

Plato’s Republic by Simon Blackburn

Darwin’s Origin of Species by Janet Browne

Thomas Paine’s Rights of Man by Christopher Hitchens

The Qur’an by Bruce Lawrence

Homer’s The Iliad and the Odyssey by Alberto Manguel

On the Wealth of Nations by P. J. O’Rourke

Marx’s Das Kapital by Francis Wheen

Forthcoming:

Machiavelli’s The Prince by Philip Bobbitt

CONTENTS

Introduction

1The Reality of War

2The Writing of On War

3The Nature of War

4The Theory of War

Conclusion

Notes

Sources and Further Reading

A Note on Translations and Editions

About the Author

Acknowledgements

Index

INTRODUCTION

In 1975, six years after returning from his last tour of duty in Vietnam, Colonel (as he was then) Colin Powell went to the US National War College. A year later, Princeton University Press brought out a fresh English-language edition of Carl von Clausewitz’s Vom Kriege, or On War, first published posthumously in German in three volumes between 1832 and 1834. Two of the most distinguished historians of their generation, Michael Howard and Peter Paret, were responsible for the translation. Howard had fought with distinction in the Second World War: Clausewitz appealed to him as a soldier writing for other soldiers. His aim was an English version that soldiers themselves would read, and, just in case they did not, Bernard Brodie, a star of the strategic studies firmament of the nuclear age, concluded the volume with a short summary of the text. The Princeton edition of On War has proved far more successful than the German original ever was. It not only rendered Clausewitz’s prose in language that is readable and graphic (as is the original), but also gave the text an inner unity which many of its readers had denied it possessed. Over the last thirty years American soldiers in particular have responded to Howard’s hopes.

One of them was Colonel Powell. He described On War as ‘a beam of light from the past, still illuminating present-day military quandaries’. Confused by the disintegration in Vietnam of the army he loved, and alarmed by the gulf that had opened between it and the society it served, he found explanations for what had gone wrong in On War. ‘Clausewitz’s greatest lesson for my profession was that the soldier, for all his patriotism, valor, and skill, forms just one leg in a triad. Without all three legs engaged, the military, the government, and the people, the enterprise cannot stand.’1 Powell was not alone in using Clausewitz to explain what had gone wrong in Vietnam. In 1981 Colonel Harry Summers, Jr, prepared a study for the US Army War College entitled On Strategy: A critical analysis of the Vietnam war. Published in 1982, it had already been printed three times by 1983. Summers applied On War (as translated by Howard and Paret) to identify the ‘missing link’ in US strategy – ‘the failure to address the question of “how” to use military means to achieve a political end’. Summers, like Powell, highlighted Clausewitz’s ‘trinity’, which he, also like Powell, maintained was made up of army, government and people. Feeling, too, that he had to justify his use of a text that had been published 150 years before, Summers insisted ‘that this is the most modern source available’.2

Summers had no cause to be so defensive. In 1983 Powell became the senior military assistant to Caspar Weinberger, the Secretary of Defense in Ronald Reagan’s administration. Like Powell, Weinberger was determined to put the army back on its feet, and he too found inspiration from On War. In November 1984 he laid down criteria for the use of American troops abroad: ‘As Clausewitz wrote, “No one starts a war – or rather, no one in his senses ought to do so – without first being clear in his mind what he intends to achieve by that war, and how he intends to conduct it.”’3 Failing to do this in Vietnam was, in Powell’s words, ‘mistake number one’. It ‘led to Clausewitz’s rule number two. Political leaders must set a war’s objectives, while armies achieve them.’

Powell and Weinberger were attracted to Clausewitz precisely because he seemed to be so clear about the relationship between war and policy. However, in 1989 the collapse of the Soviet Union left the political context fluid and even opaque. Powell was appointed Chairman of the Joint Chiefs of Staff just as the United States’ military found itself without an equal. In 1992, as Bosnian Serbs slaughtered Muslims in the former Yugoslavia, America’s public called for its government to use military intervention. Powell’s reaction was to reiterate the Weinberger doctrine, stressing the need for clear political objectives before American ground troops were committed in the Balkans. But he went further: he rejected the use of ‘limited force’, stating that ‘decisive means and results are always to be preferred’.4 This too was a sentiment whose origins were Clausewitzian.

The American army’s other intellectual response to defeat in Vietnam had been to rethink its operational doctrine for the conduct of war, a process in which it took the German army as a model. Between 1871 and 1945 the German general staff had embraced what it called a ‘strategy of annihilation’, the achievement of a victory on the battlefield so decisive and so speedy that it would determine the political outcome. It was an idea which it traced to Clausewitz. Therefore two currents – one embracing the political purpose of war and the other the way it should be fought, but both drawing on a Clausewitzian pedigree – converged in the Powell doctrine of 1992. In the ensuing decade, the US army, increasingly conscious of its military superiority, focused on the second current, ‘decisive means and results’, to the exclusion of the first. The planning of the Iraq War of 2003 revealed that an updated version of the German ‘strategy of annihilation’ had subsumed Clausewitz’s ‘rule number one’, as ironically Colin Powell – now Secretary of State – discovered. Tommy Franks, Commander-in-Chief of the United States Central Command, was almost wilful in his pursuit of rapid operational success at the expense of long-term political goals. For him ‘the maxims of the Prussian strategist Carl von Clausewitz had dictated that mass – concentrated formations of troops and guns – was the key to victory. To achieve victory, Clausewitz advised, a military power must mass its forces at the enemy’s “center of gravity”.’5

Franks had been a one-star general in Operation Desert Storm, the war against Iraq in 1990–91. Then the forces of the United States and its allies had been able to apply the operational doctrine developed after Vietnam, and designed to counter the Soviet Union in the 1980s, to devastating effect. The question that dominated the aftermath of Desert Storm was whether its success pointed forwards or backwards. For Franks and others, focused on the operational dimension, it pointed forwards. New technologies would enable the American army to do even better next time. Franks thought that he was correcting Clausewitz (but that just showed that he had not read On War very carefully), when he concluded that, ‘the victory in Desert Storm proved that speed has a mass of its own’. Others went even further, arguing that developments in information technology would remove the fog and uncertainty that surrounded the battlefield – what Clausewitz had called friction. It was precisely this concept that had so appealed to Michael Howard’s own military experience.

Franks and his ilk saw themselves as refining Clausewitz, not rejecting him. But others – those who thought the influence of Desert Storm was retrograde – deemed On War to have lost its relevance. They detected changes not just in the character of war, but in its very nature. In 1991, Martin van Creveld published a book whose American edition was entitled The Transformation of War, and which his publishers dubbed ‘the most radical reinterpretation of armed conflict since Clausewitz’. With the end of the Cold War the Clausewitzian presumption that war is an act of force designed to fulfil the objects of policy was increasingly challenged. Clausewitz, so the argument runs, identified war with the state, not least because he presumed that only states have policies. Many of the conflicts waged since 1990 have been fought by non-state actors. Some of them fight for political objectives but do not employ the sorts of armies which Clausewitz described: instead, their tools are guerrillas and terrorists. Others wage war but not for political objectives, using conflict to mask organized crime, drug-running and money-laundering. For them the object is not peace (as it was for Clausewitz) but more war. By the late 1990s van Creveld might reasonably maintain that he had been vindicated. Mary Kaldor’s New and Old Wars, published in 1999, drew a distinction between ‘old wars’, which were those that Clausewitz had studied, and the ‘new wars’ being waged by warlords in the Balkans, whose interests demanded the continuation of conflict, not its conclusion. For van Creveld and Kaldor, Bosnia represented what war had become, and Powell – in keeping the United States out of it because he wished to wage an ‘old war’ – was trapped in a typological confusion for which Clausewitz was responsible. Van Creveld took exception to what he called the ‘Clausewitzian universe’, not just because ‘it rests on the assumption that war is made predominantly by states or, to be exact, by governments’, but also because of Clausewitz’s vision of war as ‘trinitarian’. Like Powell and Summers, van Creveld described Clausewitz’s trinity as made up of people, government and army. As we shall see, Clausewitz’s trinity was not quite like that. Moreover, how central it was to the overall picture of war which animated On War in its entirety is open to question, as are both the relationship between war and policy and exactly what Clausewitz understood by policy.

Controversy is not new to Clausewitz; indeed, he invited it. In On War he took specific aim at one easy target and one difficult one. The easy one was an officer of the Prussian army, Adam Heinrich Dietrich von Bülow, who had endeavoured, not always very successfully, to explain the impact of the French Revolution of 1789 on the conduct of war. Bülow was declared insane in 1806 and died in 1807. He was not around to defend his corner in 1832. Antoine-Henri Jomini was, and indeed lived on until 1869, dying at the age of ninety. If modern strategic thought finds its roots in the nineteenth century, Jomini has a much greater claim to be its father than Clausewitz. A Swiss by nationality, he served as a staff officer with the French army of Napoleon between 1805 and 1813, writing as he went, and then devoting the rest of his career to refining his thoughts about warfare. The military academies and staff colleges that mushroomed in his lifetime and which were themselves symptomatic of the growing professional self-regard of soldiers proved ready consumers of his precepts.

Clausewitz’s specific blows against Jomini in On War were few and glancing, rebutting what Jomini laid down as general principles. But he could be much more forthright in his other works, and became more so as he grew older. In an essay written in 1817, Clausewitz criticized both Bülow and Jomini for their development of ‘fantastic and one-sided systems’.6 One of Clausewitz’s last pieces of historical writing was an account of the 1796 French campaign against the Austrians in Italy, when the young Napoleon had revealed his incipient military genius. The campaign became the departure point for Jomini’s own analysis of how Napoleon had changed the methods of war from those of his eighteenth-century predecessors. Clausewitz said of it, on the opening page of his own account, that Jomini’s ‘narrative is insufficient, full of gaps, obscure, contradictory – in short it is everything that an overall account of events and their relationships should not be’.7

In all probability Clausewitz had not even crossed Jomini’s horizon until these words were published in 1833, two years after Clausewitz’s death, but Jomini rose to the challenge. In 1838 the Preface to his Précis de l’art de la guerre, whose qualities as a textbook established a pattern for works on strategy which has persisted until today, stated that Clausewitz has ‘an easy pen’ (significantly the French word was facile). ‘But this pen,’ Jomini went on, ‘sometimes a little wayward, is in particular too pretentious for a didactic discussion, where simplicity and clarity must be the first requirement. More than that, the author reveals himself to be too sceptical in relation to military science: his first volume is only a blast against every theory of war, while the two following volumes, full of theoretical maxims, prove that the author believes in the efficacy of his own doctrines, even if he does not believe in those of others. As for me, I aver that I have been able to find in this labyrinthine intellect only a few insights and noteworthy points; and far from having caused me to share the author’s scepticism, no work has contributed more than his to make me aware of the necessity and usefulness of good theories.’8

Jomini’s criticisms of Clausewitz are worth quoting at length, precisely because they have never been wholly dismissed. Between 1834, when the last of the three volumes of On War was published, and 1871, Clausewitz was little read outside his native Prussia. Partly this was a consequence of his having written in German, a less accessible language to the literati of Europe than French. A Belgian artillery officer, Neuens, translated On War into French in 1849–51, and La Barre Duparcq, an instructor at St Cyr, France’s military academy, then wrote a commentary on the text in 1853. Duparcq’s reactions mirrored those of Jomini. He thought On War contained many insights but peddled false judgements and lacked overall clarity. For Clausewitz’s fellow Prussians there were plenty of other works to read, even if none matched the ambition of his conception. When the publishers of On War somewhat optimistically decided to bring out a second and revised edition in 1853, the first printing of 1,500 copies had still not sold out. In 1857, a famous military commentator of the day, Wilhelm Rüstow, while comparing Clausewitz to Thucydides and saying he was ‘good for all times’, confessed that he ‘has become well known, but is very little read’.9

Like Jomini’s judgement, Rüstow’s has never lost its force. However, Prussia’s stunning and rapid victories over Austria in 1866 and France in 1870–71, culminating in the unification of Germany, inaugurated the first true discovery of Clausewitz. The German army now became the model for Europe, and Clausewitz was cast as its intellectual father. On War was translated into English by J. J. Graham in 1873. Four more German editions of On War were published before the First World War, and the fifth, published in 1905, had a Foreword by the Chief of the General Staff, Alfred von Schlieffen. Six editions appeared during the war itself, together with a host of abridged versions and short guides.

It is not at all clear why this should have been the case. In his old age, the architect of Prussia’s victories, Helmuth von Moltke, included On War in a small clutch of books which had influenced him, alongside more predictable titles such as the Bible and the works of Homer. It became axiomatic that Clausewitz was Moltke’s spiritual father. But there is no evidence to suggest that their paths crossed when Moltke was at the War Academy in the 1820s; although Clausewitz was its director, he did not teach. As Chief of the General Staff, Moltke trained his officers through practical exercises like staff rides and war games, not through works of theory. Certainly, if Moltke took anything from On War, it was not the precepts on war’s relationship to policy or its ‘trinitarian’ nature in the terms which they came to be understood by Colin Powell or Martin van Creveld. Famously, Moltke rebutted the efforts of Prussia’s Minister President (and Germany’s first Chancellor), Otto von Bismarck, to assert the primacy of policy during the course of the Franco–Prussian war, claiming that policy’s influence was decisive only at the opening and at the end of a conflict. ‘Strategy has no choice but to strive for the highest goal attainable with the means given,’ he said in 1871. ‘The best way in which strategy can cooperate with diplomacy is by working solely for political ends but doing so with complete independence of action.’10 Prussia achieved a crushing victory over Napoleon III at Sedan on 1 September 1870 but the war was prolonged until 10 May 1871. With the fall of Napoleon, the Third Republic resolved to wage a war of national resistance. Moltke’s response to this intervention by the people was not to recognize the war’s ‘trinitarian’ nature but to do his best to deny it – to say that France’s guerrillas flouted the laws of war and to affirm that in Germany’s own case the army, although it was conscripted, should embrace an ethos that derived not from the people but from the monarchy and its officer corps.

Gerhard Ritter, the great historian of German militarism, concluded that Moltke’s conceptions, ‘despite the fact that they deliberately hark back to certain formulations by Carl von Clausewitz… represent a clear departure from Clausewitz’s basic views’. During the siege of Paris, in the winter of 1870–71, when the clash between Bismarck and Moltke reached its height, Moltke declared ‘political elements merit consideration only to the extent that they do not make demands that are militarily improper or impossible’.11 This was an opinion that was indeed incompatible with the parts of On War on which Ritter and subsequent commentators have focused – that is the first and last of its eight books, and in particular the first book’s first chapter. It is here that the most cogent expression of war’s relationship to policy is to be found, and it is this chapter which concludes with the ‘trinity’. Moltke and his contemporaries read the intervening books of On War just as – if not more – carefully, precisely because they described the Napoleonic wars whose paradigm (not least thanks to Jomini) dominated military thought until 1914. The wars of German unification were short, sharp and decisive. That was both a Napoleonic and a Clausewitzian ideal. Battle settled strategy. What Moltke and his immediate successors understood by strategy was exclusively military, somewhat closer to today’s usage of ‘the operational level of war’. It was here that the key debates about military theory took place between 1871 and 1914. Strategy was what generals and their staffs did (and they, after all, were the most likely readers of a big book on war); it underpinned manoeuvres and exercises; and it guided the plans with which they embarked on hostilities in 1914 itself. In 1866 and 1870 Moltke had achieved decisive success because his armies had converged on the battlefield from different directions, so taking his opponents in the flank and rear as well as from the front. Although Napoleon had done the same thing, not least in his early campaigns in Italy, Clausewitz did not endorse the use of what soldiers call envelopment. In this he and Jomini were at one, and the latter – still alive in 1866, if not in 1870 – criticized Prussia’s conduct of the war with Austria for that very reason. Moltke engaged with On War because he engaged with, and decided to modify, classical strategy, not policy. Writing in 1871, Moltke concluded in one of the rare passages where he cited Clausewitz directly: ‘General von Clausewitz… said “Strategy is the use of the engagement for the goal of the war”. In fact, strategy affords tactics the means for fighting and the probability of winning by the direction of armies and their meeting at the place of combat. On the one hand, strategy appropriates the success of every engagement and builds upon it. The demands of strategy grow silent in the face of a tactical victory and adapt themselves to the newly created situation.’12

Moltke and his successors saw On War as a discussion as much of the relationship between tactics, or what armies do on the battlefield, and strategy, or the use of the results they achieve on the battlefield, as of that between war and policy. And they were not wrong. In particular, Clausewitz’s attention to issues of morale and courage, of will and insight, seemed even more relevant in the tactical conditions of the late nineteenth century than they had been at its beginning. Industrialization had transformed the battlefield into a fire-swept zone, traversed by breech-loading rifles, machine guns and quick-firing artillery. It had also sucked populations out of the countryside into the big cities. There, the combination of slum-dwelling, vicious leisure pursuits and urban decadence seemed to be breeding people that were unfit, both physically and psychologically, for the rigours of war.

France’s love affair with Clausewitz made these points even more obvious than did Germany’s. As the defeated power after 1871, France had more cause to look at the sources of Germany’s success than did Germany itself. In 1885 Lucien Cardot lectured on Clausewitz at the École de Guerre, and in 1886–7 Lieutenant Colonel de Vatry produced a fresh translation of On War but significantly only of Books 3 to 6, those most concerned with Napoleonic warfare and those in which Vatry himself reckoned strategic principles were most clearly enunciated. These were not the books of On War which so impressed Colin Powell or which underpinned Martin van Creveld’s ‘Clausewitzian universe’. Vatry did go on to translate the rest of On War, but significantly Clausewitz’s best-known French interpreter of the period, Georges Gilbert, said that he need not have bothered. In 1890 Gilbert declared that Clausewitzian theory could be summarized in three laws: to act simultaneously with all forces concentrated; to act quickly and most often with a direct blow; and to act without pause.13

Among Cardot’s and Gilbert’s auditors at the École de Guerre was the man who in 1918 would command the combined French, British and American forces on the Western Front in the First World War, Ferdinand Foch. In a series of lectures delivered at the École de Guerre in 1901, Foch said that the defeat in 1871 had woken the French to the fact that the nature of war was to be understood through history, that this was the method that Clausewitz had used, and that ‘in the book of History, carefully analysed’, Clausewitz had found ‘the living Army, troops in movement and action, with their human needs, passions, weaknesses, self-denials, capacities of all sorts’. Moral forces and will power were crucial to victory. However, because both sides aspired to superiority in these respects, the enemy ‘will only consider himself beaten when he is no longer able to fight: that is, when his army shall have been materially and morally destroyed’. ‘Therefore’, Foch was able to conclude, ‘modern war can only consider those arguments which lead to the destruction of that army: namely battle, overthrow by force.’14 Clausewitz expressed himself in just such terms, as Foch himself demonstrated by direct quotation.

This was the Clausewitz to whom the British military commentator Basil Liddell Hart would take such strong exception after the First World War. During the war Foch put into practice what he preached, or at least he never specifically retracted it. Foch, Liddell Hart wrote in 1931 in a biography of the French marshal, ‘had caught only Clausewitz’s strident generalizations, and not his subtler undertones’. Thus Liddell Hart’s Clausewitz was one mediated by the generals of the First World War. The implication in his criticism of Foch was that there was another Clausewitz. But if he really believed that, he never acted on it. In Liddell Hart’s mind the guts of the problem lay not with Foch, but with Clausewitz himself: ‘The ponderous tomes of Clausewitz are so solid as to cause mental indigestion to any student who swallows them without a long course of preparation. Only a mind developed by years of study and reflection can dissolve the solid lump into digestible particles.’15 In his Lees Knowles lectures, delivered at Cambridge in 1932–3, Basil Liddell Hart blamed Clausewitz for the slaughter of the First World War, memorably but somewhat meaninglessly dubbing him ‘the Mahdi of Mass’. He declared that, ‘Clausewitz’s principle of force without limit and without calculation of cost fits, and is only fit for, a hate-maddened mob. It is the negation of statesmanship – and of intelligent strategy, which seeks to serve the ends of policy.’16

If Liddell Hart had been right, there would have been no need for Martin van Creveld and others to have declared Clausewitz dead after the Cold War; he would already have been knocked from his pedestal after the First World War. Indeed, in France and Britain (where his perch had in any case been much rockier) he was. But that did not apply in his homeland.

Defeat in 1918 prompted Germans to return to Clausewitz, not to ditch him. This time round, however, they read him in different ways. The second discovery of Clausewitz was pioneered less by soldiers, as had been the case after 1871, than by academics. Before the First World War, Hans Delbrück, himself a veteran of the Franco–Prussian War and a professor in Berlin, had argued that, if Clausewitz had lived, he would have gone on to develop a system for strategy that would have recognized two different forms of waging war. The first would have been a strategy of annihilation. The second would have been a strategy designed to wear the enemy out, so that he would agree to negotiate. Delbrück had argued, somewhat tendentiously, that the king of Prussia, Frederick the Great, had tried to do the second of these in the Seven Years War between 1756 and 1763, an interpretation vigorously contested by the historians of the General Staff. In some respects, both sides were reflecting the preoccupations of their own callings. Delbrück was looking at strategy in a political context; Frederick sought a negotiated peace because Austria was confronted by an alliance of France, Russia and Prussia, and so was not strong enough to hope for more. The General Staff conceived of strategy in a military or operational light: for them Frederick sought battle, not shunned it, especially when it gave him the opportunity to deal with one of his enemies in isolation. The German army entered the First World War convinced that there was only one way to fight a war, and that way was the strategy of annihilation resulting in complete German victory: its operational thought was scaled up to the level of policy.

Delbrück maintained a running commentary on the war as it unfolded and after it was over renewed his attacks on the army’s approach to strategy – and especially on Erich Ludendorff, the de facto head of the German army between 1916 and 1918. What Delbrück’s extrapolations from On War brought out was the role of dialectics in Clausewitzian thought. Books 3 to 5 of On War, those on which many military theorists of 1871 to 1914 had concentrated, described a unitary conception of war, predominantly derived from the Napoleonic wars and concerned with strategy in an operational sense; both the beginning of On War, Books 1 and 2, and the end, Books 6, 7 and 8, allowed for alternatives. Even as the First World War ended, a youthful German scholar, Hans Rothfels, was putting the finishing touches to his doctoral thesis on Clausewitz’s early career and its role in the formulation of his ideas. The parallel seemed direct. In 1806, Prussia was defeated by France. Clausewitz had found himself in the same position as many young Germans in 1918. His own life and times therefore became important to the interpretation of his work. On War was not to be read as a staff college manual, in bits, but as a whole, and it was to be seen in the context of the philosophical ideas which underpinned it. At the operational level, this involved the rediscovery of Book 6, with its declaration that the defence was stronger than the offence, a precept with particular resonance for those who had fought in the trenches in 1914–18, and who also found fresh merit in Clausewitz’s description of battle as a form of attrition. But the most important consequence of this spate of activity, and particularly of Rothfels’s own work, was the reconsideration of what Clausewitz had said about the relationship between war and policy.

The German army convinced itself that it had not lost the First World War, but that in November 1918 revolution at home had precipitated defeat. The so-called ‘stab in the back’ led it to pay more attention to the third element of Clausewitz’s ‘trinity’, the people. Ludendorff recognized that war now involved the full mobilization of the entire resources of the nation. In a book published in 1922, Kriegführung und Politik, Ludendorff began with a respectful discussion of Clausewitz’s ideas, which said (not quite accurately) that for Clausewitz policy meant only foreign policy, not domestic policy, but that the First World War, which for Germany was a war for existence, showed that references to policy in On War should now be understood to apply to both. Moreover, as his title made clear, the conduct of war, Kriegführung, should be put ahead of policy: the latter should serve the former, and not vice versa. In Der totale Krieg, which appeared in 1935, he went further. The proper translation of this title is not ‘total war’, but, as the English edition (which is called The Nation at War) makes clear, ‘totalitarian war’. Ludendorff’s attention was not on how to wage war against an enemy in the operational sense, but on how to mobilize the whole state for war. ‘All the theories of Clausewitz should be thrown overboard,’ he wrote. ‘Both warfare and politics are meant to serve the preservation of the people, but warfare is the highest expression of the national “will to live”, and politics must, therefore, be subservient to the conduct of war.’17

Ironically, therefore, Ludendorff joined Liddell Hart in blaming the conduct of the First World War on Clausewitz. For Ludendorff, the problem was that the First World War was so different from earlier wars that On War had saddled Germany with a conception of war’s nature that was too limited. Liddell Hart on the one hand wanted to demolish Clausewitz because he wanted to restrict war; Ludendorff on the other wanted to abandon him because he wanted to widen the scope of policy: ‘like the totalitarian war, politics, too, must assume a totalitarian character’.18 Ludendorff therefore acted as a bridge between the ideas of the German General Staff in 1914–18 and the rhetoric of Fascism. By eroding the distinctions between war and peace, and defining politics as an existential struggle for survival, the Nazis imported the vocabulary of war to daily life. But, contrary to Ludendorff’s beliefs, totalitarianism did not imply the death of Clausewitz. Karl Haushofer, the professor of geopolitics at Munich and himself a National Socialist, delivered a copy of On War to the political prisoners held in Landsberg prison after the failed Nazi Putsch of 1924. In 1933, as the Nazis seized power, he wrote to one of them, Rudolf Hess, ‘Remember the word of Clausewitz, so that you yourself can rouse the German nation to life again.’19 The Clausewitz who appealed to the Nazis was less the theorist of war whom Ludendorff rejected and more the spokesman of an existential conflict with Napoleonic France, whom the academics had discovered but Ludendorff had overlooked. ‘Not all of you may have read Clausewitz, and, if you have read it you have not understood it and realized how to apply it to the future,’ Adolf Hitler told an audience in Munich on 9 November 1934. ‘Clausewitz writes that recovery is still always possible after a heroic collapse… It is always better, indeed necessary, to embrace an end with horror than to suffer horror without end.’20

In April 1945, less than nine years later, these words would acquire an awful reality for the German nation as the Red Army closed on Berlin. Hitler did indeed embrace ‘an end with horror’ in a battle which represented the clash of two contrasting interpretations of Clausewitz’s thinking on the relationship between war and policy. On War was not translated into Russian until 1902, and inadequately even then. But a fresh version appeared in 1932–3, and it had reached its fifth Russian edition by the time of the German invasion of Russia in 1941. The appeal of Clausewitz to totalitarian governments was therefore confirmed by his reception in the Soviet Union. In 1858 the founding father of Communism, Karl Marx, had written of Clausewitz, that ‘the fellow has a common sense that borders on wit’.21 The Bolshevik party leader, V. I. Lenin, was particularly taken by Clausewitz’s formulation that war was waged for the ends of policy and made extensive use of On War when he wrote his essay on socialism and war while in exile in Switzerland in 1915. After the Russian Revolutions of 1917, Lenin’s chief executive, Leon Trotsky, tried to balance the political imperatives of revolutionary socialism with military realities as he set about the creation of the Red Army. For him, the dialectical approach of Books 1 and 8 held a particular appeal: ‘We must reject all attempts at building an absolute revolutionary strategy with the elements of our limited experience of three years of civil war during which army sections of a special quality engaged in combat under special conditions. Clausewitz has warned very correctly against this.’22

The symmetry between Marxism–Leninism and Clausewitz was challenged by the bitter fighting of the Russo–German war of 1941–5. By 1945 Clausewitz laboured under three besetting sins in Russian eyes: first, he was German, and therefore his ideas were those of the enemy; second, German military thought had been responsible for two world wars; and third, the German way of war had proved remarkably unsuccessful in both, resulting in successive and resounding defeats. The problem of Lenin’s enthusiasm for On War was dealt with by explaining that he never addressed the specifically military side of Clausewitz’s thinking. What appealed to Lenin was the observation that war was a continuation of policy, but that attracted him because he was a Marxist, and Clausewitz, self-evidently, was not. In February 1946, the party leader, Josef Stalin, declared that Clausewitz was out of date, ‘a representative of the age of manufactures in war’, whereas ‘now we stand in the machine age of war’.23

Once again Clausewitz seemed to be dead and buried, and indeed to all intents and purposes in the Soviet Union he was – at least until Stalin was. But in 1956, the year in which Nikita Khrushchev’s speech to the twentieth party congress condemned not only the policies of his predecessor, Stalin, but also his conduct of the war in its opening phases in 1941, Clausewitz’s rehabilitation in Soviet military thought began. Using Lenin to legitimate their own thinking, Soviet military writers sought to integrate the destructiveness of nuclear weapons within the framework of inevitable class struggle. They argued that war was both a tool of policy – in the sense that policy initiates war and determines its objectives – and that policy governs strategy, so shaping the way that the war is conducted. Marxism–Leninism made Soviet soldiers the purest of Clausewitzians, even to the point of accepting their own subordination to political authority, on the understanding that the government itself comprehended the nature of the military instrument that was at its disposal. However, there was also an implicit split between Soviet strategic thought, which incorporated nuclear weapons within mainstream military doctrine, and Soviet policy, which recognized that their destructive effects could outstrip any political gain. As the Soviet dissident Andrei Sakharov recognized, nuclear weapons seemed to invalidate all the standard propositions put forward by the fusion of Marxism–Leninism and Clausewitz: ‘if Clausewitz’s formula were applied across the board in our day and age, we would be dealing not with the “continuation of politics by other means” but with the total self-destruction of civilization’.24

Therefore, at its height the Cold War suggested that war could not be the means to fulfil the objectives of policy. However, again the text of On War provided its own basis for Clausewitz’s resurrection. German scholars, like Gerhard Ritter, anxious to discard the Nazis’ appropriation of Clausewitz in explaining and justifying ‘total war’, argued that in On War ‘politics in no way appears as the intensifying element, but as the moderating’.25 In France, Raymond Aron used Clausewitz’s interest in dialectics to follow through the logic of his own arguments, left unfinished by his death in 1831. In Penser la guerre, Clausewitz, published in 1976, Aron extrapolated from the implications of Book 6 of On War, which stated that defence is stronger than offence, to conclude that Clausewitz would have gone on to develop a theory of conflict resolution: the war-mongering Prussian was being transmogrified into a liberal theorist of international relations.

Nuclear deterrence gave the threat of war, rather than war itself, a political utility, and so could be treated in Clausewitzian terms. Moreover, limited wars were being waged under the nuclear umbrella. Here the salience of political utility was even more marked than in the major wars that had characterized most of Clausewitz’s analysis. In The Nuclear Question, published in 1979, Michael Mandelbaum began with Clausewitz’s conception of ‘absolute war’, a phrase Clausewitz originally coined to characterize the Napoleonic wars, to show that ‘the logic of war, as Clausewitz defined it, is Hiroshima’. But he then went on to say that ‘real wars do not become absolute. There are natural barriers that limit war’s violence. And there is a man-made barrier as well; the political control of force.’26 The role of policy in relation to war was now to enable the waging of limited, not major, war. Clausewitz’s legacy was being appropriated not by Nazis or Bolsheviks, but by the democratic states of the West.