Clausewitz wrote his History of the Campaign of 1815 sometime during what proved to be the last three working years of his life: between July of 1827, when he decided to undertake a thorough revision of the manuscript that would become On War, and the spring of 1830, when he left Berlin to take up an operational assignment as inspector of artillery in Breslau. A few months later he was named chief of staff of the Prussian forces that were being assembled to observe, and if necessary to suppress, revolutionary agitation in Poland. It was in the course of the latter assignment that Clausewitz contracted the cholera from which he died the following year, leaving On War in the unfinished state in which it has come down to us. The undated manuscript of the Campaign of 1815 was found among his surviving papers and included among the collected works published under his wife’s supervision a few years later.
In contrast to On War, which Clausewitz intended to publish someday, the Campaign of 1815 does not appear to have been destined for anyone’s eyes but his own. He suspected, as he wrote to his friend Carl von der Groeben, that most readers would be bored by the historical work with which he was engaged, because it amounted to no more than “a collection of analyses and proofs,” and was strictly focused on “the resolution of strategic questions.” He had made no attempt to capture “the total impression of external events,” so he could not imagine placing such work before the public.
Von der Groeben, who assisted Marie von Clausewitz in the posthumous publication of her husband’s works, did not share Clausewitz’s sense that people would not be interested in what he had to say about the history of war. Yet it is true that the Campaign of 1815 does not present a comprehensive account of its subject. Viewed as a freestanding study it makes a somewhat odd impression, if for no other reason than because Clausewitz has contrived to drain every trace of fear and exaltation from events that must have included plenty of both. The proportions are also peculiar. Some tactical episodes are analyzed in detail—the Prussian effort to hold onto the village of Saint-Amand outside Ligny, for instance. Others, like the unyielding struggle to control the château of Hougoumont, or the relentless fire that Napoleon’s grande batterie poured onto Wellington’s forces throughout the day at Waterloo, are passed over in a few words or in silence. Overall the climactic struggle at Waterloo gets scarcely more attention than the (admittedly under-rated) Battle of Ligny that preceded it. This imbalance might be interpreted as an expression of Prussian patriotism, were any hints of such patriotism evident, which they aren’t. And while Clausewitz makes occasional reference to the limitations of his sources, his personal role in the campaign, as chief of staff to Thielmann’s corps, is completely effaced. So too are whatever reminiscences might have been conveyed by his life-long friend and patron Neidthardt von Gneisenau, who was Blücher’s chief of staff and must have been privy to all major strategic decisions on the Prussian side; not to mention the memories of any number of brother officers, who were present on the day and were still Clausewitz’s colleagues during the years he was working on the manuscript.
The Campaign of 1815 does not include the intimate portraiture that enlivens many of Clausewitz’s earlier historical works. There is nothing in it to compare to his incisive survey of the military and political personalities who led Prussia to defeat in 1806, nor to his shrewd portraits of the men who led the armies that expelled Napoleon from Russia in 1812. Such personal excursuses were integral to Clausewitz’s analysis of these earlier campaigns. Having declared at the outset of his history of the campaign of 1806 that “Prussia … was wrecked by its institutions,” it was only right to take account of the personalities, assumptions, and capabilities of the men those institutions had brought to the forefront of Prussian life. And while that account did not absolutely require that the senior Prussian general at the Battle of Jena be described as a man “suited to carry out the orders of others,” it is apparent that such unflinching candor gave Clausewitz’s study an explanatory precision that no purely operational analysis could match.
The same can be said of his portrayal, in The Campaign of 1812 in Russia, of the ageing Russian field marshal, Mikhail Kutusov, sitting passive and bewildered in his headquarters at Borodino while Napoleon pounded away at his army and his aides ran to and fro with bold proposals for how to set things right. This spectacle compared poorly with the more decisive style of Kutusov’s predecessor in supreme command, General Barclay de Tolly, whom Kutusov had relieved only a week before. Clausewitz, an outsider who spoke no Russian, did not feel entitled to challenge the consensus within the Russian army that most of the time Kutusov “counted for nothing” in the course of the battle. And he admits that Kutusov’s performance was “anything but brilliant, and far beneath what could have been expected of him in view of his earlier achievements.” But even so, Clausewitz was not so sure whether, in the end, Kutusov might not have been the best choice to lead the army though its most bruising confrontation with Napoleon. Kutusov, he concluded:
would certainly not have fought the battle of Borodino, which he probably did not expect to win, if it had not been pressed upon him by the court, the army, and the whole country. Presumably he regarded it only as a necessary evil. But he knew his Russians and understood how to treat them. With astonishing boldness he presented himself [afterwards] as the victor, announced everywhere the impending destruction of the enemy army, gave the impression, up to the last moment, that he intended to defend Moscow with a second battle, and did not hesitate to bluster and boast. In this way he flattered the vanity of the army and the people; with proclamations and religious addresses he tried to work on their feelings and thus created a new kind of confidence, artificial to be sure, but based on a fact, namely the miserable situation of the French army. The frivolity and hucksterism of the old fox were in fact far more useful than Barclay’s honesty would have been.
With the exception of Clausewitz’s withering account of Napoleon’s behavior at the very end of the Battle of Waterloo, which is discussed below, this sort of rich observation is missing from the Campaign of 1815. It has been almost entirely displaced by a single-minded concentration on the logic of events, and specifically on the command decisions that bring the events about. The Waterloo campaign was already world-famous when Clausewitz decided to write about it. Whatever might have drawn his attention to it, it cannot have been a desire for a more thorough acquaintance with the facts. Although Clausewitz’s text includes a list of tactical issues on which he would have liked additional information, the truth is that the facts were sufficiently known. It was their authorship, so to speak, that interested him. It is for this reason that his most important source is also the one that is least reliable in factual terms: Napoleon’s Mémoires. The ultimate subject of Clausewitz’s history of 1815 is the minds of the men who commanded the armies that fought it. Clausewitz's approach to the greatest military campaign of his age is not that of a soldier recounting a famous victory, but more in the spirit of a critic engaging a long-familiar text in order to reconstruct the creative process by which it came to exist.
It is natural, considering when it was written, to interpret the Campaign of 1815 as an exercise that Clausewitz must have undertaken in connection with the proposed revisions of On War that he described in his note of July 1827. Yet references to the Waterloo campaign are rare in On War—eleven altogether, none terribly interesting. All appear in sections of the book that Clausewitz declares in his note to be in need of complete overhaul, which they evidently did not receive. There is thus no particular reason to believe that writing the Campaign of 1815 altered the composition of On War in any substantial way. It would be more accurate to say that the themes and insights that Clausewitz intended to emphasize in revising On War are also on display in his account of Napoleon’s last campaign. This was written after most, if not all, of the text we know as On War was complete.
In the note of 1827, Clausewitz declares his intention to revise On War in light of two fundamental principles. The first of these principles is that wars can be of “two kinds”: those with limited objectives, intended to bring about negotiations, and those intended to bring about the complete overthrow of the enemy. The second is that “war is nothing but the continuation of policy with other means.” Both of these principles make themselves felt in the Campaign of 1815, though the influence of the first is perhaps not obvious. If ever there were a clash of arms intended to bring about the complete overthrow of the enemy, one may well feel that Waterloo must be it. But this is true only on the Allied side. Napoleon’s political aims in 1815, at least with respect to the Allies (as opposed to the Bourbons, whom he had already displaced), were quite limited. He was fighting to achieve some kind of military result that could serve as a basis for negotiation. This fundamental political fact serves Clausewitz as the touchstone against which Napoleon’s military actions had to be judged if they were to be properly understood.
The natural way in which Clausewitz accounts for the political objectives of Napoleon and his adversaries, and integrates this understanding into his analysis of major operations, marks the Campaign of 1815 as one of his most mature and sophisticated historical works. It also illustrates the general value of reading his historical studies alongside On War, in which theoretical insights of great value are often accompanied by historical illustrations that either fail to do them justice or inadvertently limit the point Clausewitz is trying to make. The outstanding example of this is undoubtedly the famous passage, at the end of Book One of On War, in which Clausewitz describes war as a “remarkable Trinity” comprising “primordial violence,” the “play of chance and probability,” and finally “reason,” which is the “element of subordination” that defines war’s instrumental nature. This striking passage is immediately followed by another, intended to clarify it, in which the three elements of the Trinity are identified respectively with “the people,” “the commander and his army,” and “the government.” As a consequence, any number of readers have concluded that Clausewitz’s Trinity—whose true elements are violence, chance, and reason—is instead basically sociological in nature; that its constituent elements are the people, the army, and the government; and that some kind of institutional or moral balance among these is required to achieve strategic success.
This is clearly a misreading, but one that Clausewitz invites by pegging his general theoretical claims to historically contingent social and political conditions. It may be true, as was widely believed after the French Revolution, that the “violence, hatred, and enmity” of war, which make it seem like “a force of nature,” will often concern “mainly … the people.” But this is not always the case. It was not the case in the campaigns of Frederick the Great, for instance, and it was not the case in 1815, either. The Waterloo campaign, in Clausewitz’s account, is one in which the armies of France are driven to battle by the primordial passions of their commander, whose hatreds and enmities were merely echoed, and faintly at that, by the nation whose destiny he had seized.
Clausewitz’s claim that there are two kinds of war has aroused similar confusion. While the metaphor of the Trinity may be so complex as to elude all but the most attentive reader, the claim that there are two kinds of war is at the very least a misleading oversimplification. As Clausewitz declared elsewhere (and obviously believed), all wars are things of “the same nature,” whose shared recourse to violence is the one thing that distinguishes all war categorically and collectively from the other instruments of policy. That Clausewitz should have sought to draw such an emphatic distinction across a phenomenon that he also describes as “diverse” and “chameleon”-like has, at the very least, raised more questions than it has answered. The answers are apparent, however, in The Campaign of 1815. There the analytic importance of understanding the political motives that govern war is on display in subtle and convincing form.
Clausewitz’s claim that war can be of two kinds is a needlessly unconditional expression of a point that he believed required great emphasis: that the scope and character of a belligerent’s political aims matter to the conduct of war, not merely on the margins or at the beginning and the end, but centrally and throughout the entire course of the fighting. One way to illustrate this, as Clausewitz does by implication in his example about the seizure of a province, is to observe that most wars are small because the political stakes are small. But this is an empirical observation rather than a theoretical principle, and if it is mistaken for the latter it implies a rule of proportionality between military means and political ends that is clearly false. Clausewitz himself would have rejected such a rule as one of those unrealistically “algebraic” propositions that so often confound strategic analysis.
Napoleon had limited means and limited objectives in 1815, but nevertheless found himself in a situation that demanded the greatest possible military effort, a common enough predicament of the weaker side in war. His circumstances were complicated by the fact that his objectives were entirely psychological. There was no way he could inflict sufficient material damage on his opponents to alter their overwhelming military advantage. Instead he needed a victory of sufficient significance to shake the alliance that had assembled against him. When added to his own formidable reputation, such a victory would suggest to his opponents that only a disproportionate amount of additional fighting would suffice to subdue his new regime—disproportionate, that is, compared to the distasteful but easier course of acquiescing in his return to the throne of France. Wellington and Blücher, on the other hand, would have been perfectly satisfied to see him hung from a gibbet—the quintessential “unlimited” objective in Clausewitzian terms—and they enjoyed sufficiently overwhelming superiority of numbers that they did not need to calculate their own costs or risks too closely. If they did not possess the full measure of Napoleon’s brilliance, neither did they suffer from his political and material constraints. This is why, in the end, the fortunes of war favored them.
Clausewitz’s understanding of the political aims of Napoleon and his opponents is crucial to his tactical analysis. It is a tool by which he can work backwards from the known facts of the campaign to the reasoning and assumptions of the commanders whose decisions, modified as always by the effects of friction, chance, and the interaction of the opposing armies, brought those facts about. Yet there is no avoiding the additional fact that, in political terms, the outcome of the Waterloo campaign was severely over-determined. Napoleon was well and truly at bay, with half a million men and more converging against him and no more than a few weeks to get ready. Under such circumstances it is easy to argue that, realistically, the details of the fighting mattered very little. When all roads lead to defeat, the choice among them makes no difference, except to those seeking purely tactical instruction.
This is a problem that all serious students of Waterloo must confront. Two sorts of answers are available. The first is that there is more than one kind of historical realism, and the most important kind takes full account of contemporary perceptions. The degree to which Napoleon’s fate was sealed in 1815 is more apparent in retrospect than it was to those who had to face him. For them he was a figure of near-demonic power, who had escaped certain doom once before in Russia and lived to fight another day. The hand-wave with which he had sent the Bourbons packing confirmed this impression. Napoleon’s capacity to wreak havoc could scarcely have been viewed with complacency even if one were confident of the military results. This leads to the second sort of answer, which is that, when fighting Napoleon, one could never be confident of the results until they had actually been achieved. From this perspective, Napoleon’s cause is not to be regarded as hopeless at all: A great victory against Wellington and Blücher might indeed have broken the coalition that opposed him and created conditions that would have allowed his reign to continue.
Clausewitz certainly held the first of these two points of view. He believed that historical (and strategic) understanding required him to recapture the way things appeared at the time, rather than to impose retrospective judgments or values upon the past. It is less clear whether Clausewitz believed Napoleon had a real chance of permanent political success. In Chapter 51 of his history, Clausewitz offers what he regards as the maximum military result that Napoleon could have achieved in 1815: a truly crushing victory over Blücher’s army, which Clausewitz argues should have been pursued ruthlessly after the Battle of Ligny, without regard for what Wellington might do in the meantime. But while Clausewitz had claimed a few pages before that “Bonaparte was balancing on the tip of his sword not only the crown of France but a number of other crowns as well,” he does not explain why he believes this, nor why the kind of victory he describes would have caused the other Allied armies that were already in motion to come to a halt.
This neglect may simply be owing to the fact that Napoleon did in fact lose everything at Waterloo, so that an analysis of the political weaknesses of the Allies was not necessary. Clausewitz had long been aware of the special problems of coalition warfare and of the cross-purposes that might lurk behind declarations of mutual loyalty. He also suspected, with good reason, that Austria’s commitment to Napoleon’s destruction was not all that it might have been. Austria’s attitude toward France was always moderated by concern that a serious decline of French power would accrue mainly to the benefit of Russia. During the campaign of 1814, which culminated in Napoleon’s first abdication, Austria’s chancellor, Metternich, had sought a negotiated settlement until almost the last moment. This policy was presumably strengthened by the fact that Napoleon was married to an Austrian princess, and that the heir to his throne would have been a grandson of the Habsburg emperor. Napoleon hoped to reawaken Metternich’s passion for moderation by beating Wellington and Blücher so badly that the Habsburgs would reconsider their options once more. But since he failed, the issue of Allied cohesion had never emerged in reality. Clausewitz may therefore have felt that no useful purpose could be served by considering it in hypothetical terms.
Overall, Clausewitz’s assessment of Napoleon’s chances in 1815 might fairly be described as agnostic. For his purpose it is sufficient that neither Napoleon nor his opponents regarded the outcome as having been decided in advance, even if a dispassionate judgment in retrospect might suggest that it had been. Clausewitz’s sense of balance seems to have grown more sure with the passage of time, as can be seen if one compares the Campaign of 1815 with some of his earlier work. The campaigns of 1806 and 1814 present different versions of the same analytic problem posed by Waterloo: how to treat the instrumental reality of war in political circumstances that appear to render merely military decisions inconsequential.
Clausewitz’s work on the campaign of 1814 dates from the early 1820s and took the form of two separate manuscripts. These appeared side by side in the seventh volume of his Hinterlassene Werke. The first is an “overview” of the campaign, which summarizes the order of battle of the two sides and the course of the fighting. The second, called a “strategic critique,” is concerned with “the processes of strategic thought,” which Clausewitz believed the fighting of 1814 revealed with exceptional clarity. His primary reason for thinking so, however, is startling. It is that the campaign of 1814 appeared to be relatively “untouched by diplomatic considerations, which like some foreign matter douse the fire of violence,” so that “the whole concept of war and of its purpose is not as thoroughly politicized as was the case in most recent wars before the French Revolution.”
This is, to say the least, a dramatic simplification, if not an outright dismissal, of the circumstances that had finally brought all of the Powers of Europe together against France. It represents no more than the starting point for Clausewitz’s understanding of the analytic relationship of war to politics: politics serves to determine the scale and intensity of the instrumental violence employed to achieve its ends. In this relatively early work, however, Clausewitz does not seem to feel any need to consider second-order political effects, which actually shaped the campaign of 1814 profoundly. It was politics, for instance, that drove Napoleon’s need to maneuver so as to keep his army between the Allies and Paris, the loss of which would have meant losing the war. The fact that the “offensive” and “defensive” sides were especially well-defined in 1814 is as close as Clausewitz gets to considering what it might mean for someone like Napoleon to be facing certain defeat, much less how the resulting frame of mind might have influenced his choices as a commander. The latter theme predominates in his history of 1815.
While there is no denying the acuity of Clausewitz’s operational analysis in his history of 1814, a kind of unreality pervades the whole, because it is not until the end that the true balance of forces in play is fully acknowledged. Realistically, Napoleon could muster perhaps 70,000 men for a final defense of Paris, against an attacking force more than twice as large. This fact inspired the emperor to attempt a vain flanking maneuver, a “march into the blue,” which embodied the hopelessness of his cause and sealed his defeat. Such insights were within Clausewitz’s reach throughout his working life, and reveal the essential continuity of his work. In his later years, however, as the Campaign of 1815 shows, such politically informed analysis was not merely within reach but fully at his command, and available to underpin his analysis of a major campaign.
Clausewitz’s treatment of Prussia’s defeat in 1806 presents the starkest possible contrast to his account of Napoleon’s defeat in 1814. If politics are virtually dismissed from the latter account, they more or less overwhelm the former. Clausewitz felt more strongly about the campaign of 1806 than he did about any other military episode of his life. He fought in the Battle of Auerstädt as a captain, and for a time assumed command of part of the rear guard during the appalling retreat that followed. Afterwards he spent ten months as a prisoner of war in France and Switzerland. That humiliating experience deprived him of the opportunity to distinguish himself when fighting resumed on less disastrous terms in the spring of 1807, culminating in the Peace of Tilsit by which Prussia’s survival in France’s shadow was secured. When Clausewitz returned to Berlin, he joined the group of military reformers who coalesced around his friend and mentor, Gerhard von Scharnhorst, and sought to build a new base for military resistance to France. When their efforts were cut short by the onset of the campaign of 1812, however, Clausewitz resigned his commission and entered Russian service rather than fight as an ally of Napoleon.
The anger and bitterness that the defeat of 1806 inspired in Clausewitz were suppressed in his first effort to explain it. Early in 1807 he published a series of instructive but, one cannot help but feel, artificially dispassionate articles on “the great military events of 1806.” In them he portrayed Prussia’s defeat as an honest and courageous effort against a much stronger opponent. He feared, indeed, that Prussia was liable to be judged unfairly by the rest of Europe on account of the martial reputation it had acquired in the previous century. When he returned to the subject some fifteen years later, however, the question foremost in his mind was not how a small but brave state had comported itself against overwhelming odds, but exactly how the odds had become so overwhelming. “Great military events” became Prussia’s “great catastrophe.” By way of explaining the catastrophe, Clausewitz formulated an indictment of Prussia’s governing institutions and foreign policy, reaching back to the death of Frederick the Great, that was so scathing as to render his treatment of the campaign itself more or less superfluous.
There is no question that Clausewitz’s indictment of Prussia in 1806 goes too far in his scorn for everything from the leading men in Prussia’s government to the quality of the rope in Prussia’s arsenals. Yet, on balance, Clausewitz sees the politics of 1806 clearly enough, and once that light is allowed to shine bright the effect on the military analysis is searing. In Clausewitz’s judgment, Prussia had managed by a series of ill-conceived diplomatic maneuvers to lose the chance of fighting France in 1805 as part of a grand alliance including Austria and Russia. It thus found itself isolated and overmatched a year later. Its response was a swift mobilization of the army, followed by aggressive operations intended to seize the initiative from the enemy—all in accord with Frederician habits and traditions that had been hopelessly overtaken by events.
In Clausewitz’s first attempt to come to terms with the disaster that followed, he had claimed that “nothing would appear better suited to multiply our forces, than to seize the advantages of the offensive, by which we might be fortunate enough to surprise the enemy before his preparations were ready.” Once the politics of the campaign had been accounted for, however, such a move appeared absurd. It was not simply that Prussia’s chances were slim. An army that is already advancing in search of a fight, and led by Napoleon himself, is not likely to be surprised by contact with the enemy, however it may occur. But even that was not the worst of it. The fatal problem, and the ultimate vanity of the whole business, lay in the fact that even an early Prussian success, had it somehow been achieved, would have meant nothing. The most damning of Clausewitz’s “Observations on Prussia” is one of the simplest: the army that Napoleon led into Prussia in 1806 was not the only one he had. Even if the Prussians managed to beat it, how would they make good their losses in time to beat the next one?
This is not a question that Clausewitz asks about Waterloo, though he might have done so. The campaigns of 1806 and 1815 are sufficiently mirror-images of each other that it would have been easy to treat them along parallel lines. Clausewitz does this to some extent early in his text, when he considers the scale of forces that Napoleon was able to mobilize following his return. The resulting army, Clausewitz argues, fell far below the maximum force that a country like France could have mustered, owing to a combination of institutional rigidity and the shortness of time. Prussia had suffered from similar difficulties in 1806. Its defense had been conducted by a regular army that represented a small fraction of potentially available manpower, because the government had failed to provide its people with the kind of military training required to mobilize the civilian population for war. Had it been able to do so, it might then have adopted a posture of defense in depth based on the Vistula. This would have confronted Napoleon with the task of hacking his way across the entire country, with no respite until all of it had been occupied. Because the Prussian monarchy lacked the social and institutional basis for mounting such a defense, it was forced to throw away its only army in a superficially bold but doomed offensive. This is a typical expedient of the weaker side in war, as Clausewitz noted in the article in 1807, but no more likely to succeed on that account.
After 1806, Clausewitz became a strong advocate of a universal, militia-based reserve system known in Prussia as the Landwehr. He takes the opportunity, while analyzing Napoleon’s problems in 1815, to note that those problems would have been much reduced had France possessed such a system. There is some irony here. As Clausewitz observes, it was the Revolutionary levée en masse of 1793 that had inspired the system of universal military service that helped sustain Prussia’s revival. There would be no French levée en masse in 1815, however. As a consequence, Napoleon had no choice but to adopt the same kind of speculative offensive strategy that had failed Prussia nine years earlier.
It is here, of course, than any comparison between Prussia in 1806 and France in 1815 must break down. Even by the most uncharitable estimate, France was not “wrecked by its institutions,” as Prussia had been. It was wrecked, in Clausewitz’s account, by the vanity and ambition of one man. Long before he had grasped the full significance of politics for war, Clausewitz had been acutely sensitive to the role of a commander’s personality in shaping military operations. This is apparent, for instance, in his study of the campaigns of Gustavus Adolphus during the Thirty Years’ War, which he wrote following his return to Berlin in 1807. There Clausewitz declares that “subjective forces” within the mind of Sweden’s great king were the “most decisive” influence upon the actions of his army. Similarly, the failure of his Catholic opponents to concentrate all their forces against him at the crucial Battle of Breitenfeld was a reflection, not of material conditions, but of the fact that they had not yet suffered a defeat sufficiently grave to inspire a maximum effort.
These insights would crystallize in Clausewitz’s concept of “military genius.” The workings of genius pervade Clausewitz’s account of the Campaign of 1815, in which fate contrived to bring the three greatest generals in Europe together on the same battlefield. Clausewitz adapted the concept of genius from the art and literature of his time. He employed it as a means of capturing, for military theory, those qualities of talent, insight, and determination that the best commanders always display, and which cannot be explained with reference to doctrinal norms or abstract strategic principles. Clausewitz’s understanding of genius has long been recognized as owing much to the work of Immanuel Kant and to the school of aesthetic philosophy that Kant’s ideas inspired. In his Critique of Judgment, Kant defined genius as “the innate mental aptitude (ingenium) through which nature gives the rule to art,” and also as “a talent for producing that for which no definite rule can be given.” These concepts are plainly echoed in On War, where Clausewitz describes genius as a natural ability that both “rises above the rules,” and, in effect, makes them: “What genius does is the best rule,” he wrote, “and theory can do no better than show how and why this should be the case.”
Clausewitz’s histories of Napoleon’s campaigns all reflect his determination to engage with the mind of Napoleon himself, the most terrible embodiment of military genius the world had yet seen. The Campaign of 1815 is unusual in this regard only by virtue of the intimacy of the encounter. This is made possible by the fact that, in this case, Napoleon himself had provided an explanation of his conduct against which Clausewitz could test his own understanding of the evidence. Napoleon’s Mémoires pour servir à l’histoire de France en 1815 is Clausewitz’s most frequently cited source, not because of its factual value but because its misrepresentations could be used as a lens with which to bring the critical events of the battle into sharper focus. In Clausewitz’s hands, Napoleon’s Mémoires do indeed reveal the inner workings of Napoleon’s mind, albeit not in the way their author must have hoped.
In psychological terms, the fact that Napoleon felt the need to explain what had happened at Waterloo was significant in itself. He had faced apparently final defeat once before, in 1814. On that occasion he had responded by trying to kill himself, using poison that his physician had prepared for him to take into Russia two years before. The poison had lost its potency in the meantime, however, so that it had merely made him ill. Whether Clausewitz would have approved of the attempt, had he known of it, is hard to say. It would at least have conformed to a tragic and heroic ethos that he would have found recognizable.
After Waterloo, however, Napoleon did not take poison. Instead he wrote a book, an unprecedented apologia that invited close scrutiny. Napoleon’s Mémoires were significant because of their author, and because in Clausewitz’s day the death and destruction of war neither required nor received any public explanation by those responsible for it. Napoleon’s effort to justify himself was all the more intriguing by virtue of having been written by a famous liar: Napoleon’s official bulletins had been notorious for their mendacity since long before Waterloo. Yet these factors did not diminish the value of the source from Clausewitz’s perspective. On the contrary, his analysis is informed by the realization that those things that Napoleon wished to conceal were most likely to be of particular significance.
There is no denying the occasionally contemptuous tone with which Clausewitz dismisses Napoleon’s attempt to justify himself. Yet the fact of Napoleon’s genius shines through. Napoleon wrote his Mémoires to shift the blame for France’s defeat onto the shoulders of his subordinates, but also, more generally, to suggest that the Waterloo campaign as a whole was not a futile waste of blood and treasure. As with the Duke of Wellington, who famously characterized Waterloo as “a damned nice thing—the nearest run thing you ever saw in your life,” it was important to Napoleon that the campaign of 1815 be recognized as a close call, and specifically as a victory that might have been his but for bad luck and the bungling of his subordinates. The brilliance of Clausewitz's analysis lies in part in the clarity with which it reveals that this cannot have been how Napoleon saw things at the time. Napoleon fought the campaign of 1815 like a man on the edge of the abyss. As Clausewitz shows repeatedly, Napoleon’s Mémoires routinely obscured conduct that made perfect sense, or even revealed exceptional insight, once this fact is understood and the true gravity of his circumstances taken into account. But it is that very gravity that Napoleon wished to obscure, rendering his own conduct implausibly naïve in the process.
In Clausewitz’s account, it is not Napoleon’s genius that fails him in 1815, but his character. Clausewitz would have been the last person to judge the conduct of war in ethical terms. Yet there is something more than tactical judgment at work in his stunning dissection of the climactic moment at Waterloo, when Napoleon, having grasped the finality of the threat posed by the arrival of Prussian forces on his right, nevertheless commits the last of his reserves to a final, pointless attack against Wellington, rather than employing them to cover an orderly retreat.
On other occasions this is the kind of act that Clausewitz had been inclined to defend, on the grounds, as he says, that “there are situations when the greatest prudence can only be sought in the greatest boldness.” It is, moreover, a characteristic mark of genius to recognize and seize the opportunity that such situations afford. It was on this basis that Clausewitz justified Napoleon’s conduct in 1812, against the commonplace claim that the invasion of Russia was doomed from the start. Clausewitz rejected the idea that Napoleon’s defeat could have been anticipated, or that a more incremental approach would have been more promising. “It could not be foreseen with certainty,” Clausewitz argued, “it was perhaps not even likely, that the Russians would abandon Moscow, burn it down, and engage in a war of attrition; but once this happened the war was bound to miscarry, regardless of how it was conducted.”
Absent a premonition of events without precedent, Clausewitz judged Napoleon’s bold attempt to overwhelm Russia in a single campaign to be the proper choice—an example of how rule-book prudence must give way before the dictates of genius. No such defense is possible for Napoleon’s conduct at Waterloo, however. In the campaign of 1815, Napoleon is not confronted with anything like the imponderable spectacle of Moscow in flames, a harbinger of people’s war, a new “phenomenon of the nineteenth century” that exceeded the boundaries even of Napoleon’s genius. At Waterloo, on the contrary, Napoleon’s predicament is the foreseeable consequence of his own actions: warfare conducted in a manner that he had perfected, by men only slightly less gifted than himself, and no less determined.
Clausewitz could imagine war as a form of existential violence whose psychological and moral intensity carried it beyond the realm of politics. But he envisioned such conduct as the province of political communities in extremis, not of commanders throwing away the last remnants of their army rather than face up to defeat. In the end, Clausewitz deems Napoleon to have acted not “in the manner of a great man but rather in vulgar exasperation, like someone who has broken an instrument and in his anger smashes the parts to pieces on the ground.” Even for Clausewitz, genius had its limits. Those limits were reached at Waterloo, where the crushing realities of modern war had piled up so high that even Napoleon could not get past them. Yet he remained bound by war’s instrumental nature and by the interests of the political community he purported to serve. Napoleon’s ultimate duty was to that community, and to the men under his command, who were its representatives no less than he was. Clausewitz judged that, in the last hours of Waterloo, Napoleon failed in his duty. From one soldier to another, there can be no harsher verdict than that.