Decoding Clausewitz: A New Approach to On War

Jon T. Sumida
University Press of Kansas, 2008.


Posted here with permission of the author.


See Table of Contents


Carl von Clausewitz claimed that his book On War contains ideas that “might bring about a revolution” in the theory of armed conflict.1  To answer the question of why he believed this to be so, this book focuses much of its analysis upon the identification and description of those arguments of On War that challenge the conventional military theory of his day. The objective of this approach is not the explication of the text in its entirety, but rather the establishment of precise understandings of those aspects of Clausewitz’s thought and manner of thought that diverge sharply from other prominent military writers of the late eighteenth and early nineteenth century.   It is my contention that this action provides a sound point of departure for intelligent engagement with what Clausewitz believed was most original and significant in his famous treatise.   And because the kinds of military thinking that Clausewitz attacked still exert a powerful influence, his formulation of an alternative to what he held to be conventional attitudes about war remains worthy of serious consideration with respect to current military affairs.  But in the process of elucidating the nature of Clausewitzian theoretical innovation, my monograph paid inadequate attention to the Prussian author’s explanation of the concept of ‘center of gravity’, an aspect of which seems to contradict his stated views on what constitutes a proper theoretical approach.  This additional preface, which amounts to an addendum to Chapter Four of the present book, and which provides a modification of one section of the conclusions, deals with this issue.2 

In the fourth chapter of Book VIII of On War, in discussion addressed to the problem of war planning, Clausewitz puts forward his concept of center of gravity.  He defines this as “the hub of all power and movement on which everything depends.”3  Military operational success, Clausewitz contends, is about directing the maximum amount of energy against the enemy’s center of gravity.  In most cases of fighting, the center of gravity could be either the enemy army, its capital city, or the army of its alliance partner, depending upon circumstances.  But in the case of guerrilla war, Clausewitz maintains that the center of gravity of the insurrectionary force is the personality of its leaders and public opinion.4  The idea of focusing maximum effort alternatively on the enemy’s capital or the army of its ally, and not just the enemy army, amounts to a more sophisticated form of Antoine Henri Jomini’s principle of ‘concentration of [military] force.’  With respect to guerrilla war, center of gravity refers to objectives that could not be achieved through the use of concentrated force. Jomini maintains that guerrilla war is an illegitimate form of conflict, which may explain why the inapplicability of concentration of force to this category of fighting does not seem to have caused him difficulty with respect to his contention that it constituted a universally valid principle of war.  Clausewitz, on the other hand, considers guerrilla war to be an acceptable and even necessary form of war that had been brought into being by radical and irreversible political change.  He thus had to invent a more flexible concept that would encompass the use of both concentrated and non-concentrated force.  In effect, his advocacy of maximizing effort against the enemy center of gravity is an extension of the concept of concentration of force prompted by the adoption of a broader definition of the phenomenon of war.5

Clausewitz recognizes that the concept of center of gravity does not take into account all the factors that govern the outcome of fighting, and that as a consequence it simplifies the representation of the dynamics of war.  He rationalizes this departure from strict verisimilitude by arguing that since details are invariably shaped by large events, knowledge of the latter is sufficient to comprehend the former—“small things always depend on great ones, unimportant on important, accidentals on essentials,” and concludes “this must guide our approach.”6  Immediately before this declaration, however, Clausewitz contends the very opposite: that minor and undetectable factors could exert a decisive influence on the course of fighting.  After describing the dynamics of a number of different campaigns from the period 1812-1815, he writes that


these events are proof that success is not due simply to general causes.  Particular factors can often be decisive—details only known to those who were on the spot.  There can also be moral factors which never come to light; while issues can be decided by chances and incidents so minute as to figure in histories simply as anecdotes.7


Clausewitz’s promotion of reductionist theory on the one hand, and assertion in practically the same breath that theory of this kind cannot take into account decisive factors on the other, seem irreconcilable.

The appearance of theoretical conflict disappears, however, upon careful consideration of Clausewitz’s definition of the activities that make up war.  In the first chapter of Book II, Clausewitz declares that the subject of his book is the “conduct of war,” which for him means two things: planning on the one hand, and the direction of fighting on the other.8  Planning is about the integration of political and military imperatives into a clear and coherent scheme for future action.  It thus deals with a few general and what are supposed to be predictable variables.9  The direction of fighting, in contrast, is about making decisions that control the action required to implement planning.  It thus deals with numerous particular, in many cases unpredictable and even unknowable variables. 

Clausewitz believes that the relatively simple and provisional character of planning means that it could be guided productively by general propositions such as center of gravity. But he recognizes that coming to a sound understanding of the direction of fighting, which is about actual rather than projected behavior, required the careful examination of past cases of command decision.  This task, Clausewitz is convinced, posed extraordinary theoretical difficulties that earlier military theorists had either ignored or no more than palliated with inadequate theoretical instruments.  The explanation of outcomes as the product of dynamics describable by general propositions of any kind would not suffice; Clausewitz had to invent a new way to use theory that would accurately represent particular historical process.  Thus instead of studying previous cases of the direction of fighting in terms of the operation of principles of war, he calls for their examination in a way that takes account of all factors, large and small—including those for which verifiable historical facts do not exist.  To deal with the incompleteness of the surviving historical record, Clausewitz puts forward a method of combining verifiable historical fact, with surmise about unknowable variables generated by theory that describes their existence and effects.  By so doing, theory is used as a source of narrative rather than a standard of good behavior.  The result is the creation of a body of synthetic experience, not the telling of a moral tale.

Understanding of the difference between guiding war planning and studying the direction of fighting, and of their different theoretical requirements, resolves the apparent inconsistency of the quoted passages from the fourth chapter of Book VIII.   Clausewitz’s advocacy of the direct use of a general proposition is concerned with how to do war planning, while his statements about the decisive importance of variables not taken into account by such general propositions refers to the consideration of past cases of the direction of fighting. These positions are not incompatible but rather directed to two different theoretical problems, which Clausewitz had previously though distantly described in Book II.  Or to put it another way, Clausewitz admits the prescriptive use of general propositions with respect to the consideration of the yet undetermined future, but denies their prescriptive utility when considering the actual events of the past.

 In Decoding Clausewitz, I maintain that the two major arguments of On War are first, advocacy of a novel form of historical case study that takes full account of the complex, difficult, and contingent nature of operational decision-making, and second, recognition that the defense is a stronger form of war than the offense.  The former addresses the problem of how to achieve a sound understanding of the direction of fighting, while the latter deals with both the direction of fighting and war planning.  The two arguments challenge conventional military thought in fundamental ways.  Clausewitz’s concept of center of gravity, meanwhile, is not revolutionary, but rather an adaptation of a conventional general proposition that he uses in a conventional way—although his limitation of this concept to war planning, and his refusal to extend it to the direction of fighting, is unconventional.

In the conclusion, I state six arguments that describe Clausewitz’s views on the essential characteristics of sound general theory.  Given the above, the fifth can now be read as follows:


Fifth, a general theory of war must address the conduct of war, which means two things: war planning and the direction of fighting.  Deployment of prescriptive and reductionist theory is allowable as a guide in the former case, but not as an explanatory device in the latter.  With respect to the direction of fighting, theory addresses the study of the conduct of war, not the actual conduct of war; that is, the purpose of theory when dealing with an historical case is to improve the process of examining the past, a procedure that Clausewitz believes could be made scientific, not the prescription of action, which he holds can never be.


Many writers have attributed the prevalence of what appear to be contradictions in On War to Clausewitz’s supposed resort to dialectical reasoning.  The foregoing exposition, and the discussion of similarly difficult sections of On War in the main text of Decoding Clausewitz, support an alternative explanation: propositions that at first appear to be contradictory or otherwise anomalous cease to be problematical when they are related to other elements of Clausewitz’s larger analysis.

1. Carl von Clausewitz, “Note of 10 July 1827,” in  Carl von Clausewitz, On War, trans. and ed. Michael Howard and Peter Paret (Princeton, NJ: Princeton University Press, 1976), 70.
2. I am indebted to Katherine Epstein, Terence Holmes, and Jonathan Winkler for their careful reading and thoughtful criticism of an early draft of this piece.
3. Clausewitz, On War, VIII/iv: 595-6.
4. Ibid., 596.
5. For discussion of ‘center of gravity’ with respect to Basil Liddell Hart’s misreading of On War, and its relevance to Clausewitz’s arguments about guerrilla war, see the main text of this monograph (pp. 31, 32, and 173, 174).  For a careful consideration of the current use and misuse of the term by the American military, see Antuilio J. Echevarria, "Clausewitz’s Center of Gravity: It’s Not What We Thought.” Naval War College Review 56 (Winter 2003): 108-123.
6. Clausewitz, On War, VIII/iv: 596.
7. Ibid., 595.  In the standard English translation used here (Paret/Howard) the text is rendered in a way that makes it read as if the importance of minor variables is a conclusion to be drawn from the preceding description of historical events.  Clausewitz’s desciption of historical events does not, however, mention any of the variables apparently referred to in the following paragraph, which creates an impression of faulty logic.  This problem is an artifact of misleading translation.  In the original German text, Clausewitz presents his views about the importance of minor variables as an argument that augments rather than a conclusion to be drawn from his description of historical events,  for which see Carl von Clausewitz, Vom Kriege.  Werner Hahlweg, ed.  (Bonn: Ferdinand Dümmlers Verlag, 1980), 976.  This sense of the text in question is also rendered by older English translations of On War,  for which see Carl von Clausewitz, On War, 3 vols, J. J. Graham, trans. (London: Kegan Paul, Trench, Trübner, 1908), iii: 106, and Karl von Clausewitz, On War, O. J. Matthijs Jolles, trans. (New York: Random House, 1943), 586.
8. Clausewitz, On War, II/i:128.
9. For a closely reasoned examination of Clausewitz’s conception of war planning, see Terence M. Holmes, “Planning versus Chaos in Clausewitz’s On War,” Journal of Strategic Studies 30 (February 2007): 129-151.



Preface and Acknowledgments XI

Introduction 1

1. Theorists 9
Dismissal: Antoine Henri Jomini 10
Advocacy: Julian Corbell 17
Repudiation: Basil Liddell Hart 25

2 Scholars 36
Text: Raymond Aron 37
Context: Peter Paret 50
Method: W.B. Gallie 64

3 Antecedents and Anticipations 78
Historical Analysis 80
Philosophical Invention 94
Scientific Perspective 112

4 Imagining High Command and Defining Strategic Choice 121
Absolute War and Genius 121
History and Theory 135
Defense and Altack 153


Conclusions 176

Appendix One. A Pictorial Representation of Critical Analysis 195

Appendix Two. Bach's St. Mathew Passion as a Model for Critical Analysis 197

Notes 199

Bibliography 213

Index 225