Who Is Afraid of Carl von Clausewitz?

A Guide to the Perplexed


6th Edition - Summer 1997

This article was written by Dr. Michael Handel as courseware for the Naval War College. It is displayed here with his permission and is copyright Michael Handel. Dr. Handel was a Professor of Naval Strategy at the U.S. Naval War College from 1990 to his death in 2001. He was an expert on strategic theory, nature and operations of war, and the future of warfare. He held a Ph.D in Government from Harvard University. For seven years (1983-1990) he was Professor of National Security Affairs at the U.S. Army War College. He was a member of the Olin Institute for Strategic Studies at the Center for International Affairs at Harvard, founder and U.S. editor of the journal Intelligence and National Security, and author of numerous books on theory and practice of war including Masters of War: Sun Tzu, Clausewitz and Jomini (1992); Intelligence and Military Operations (1990); and War, Strategy, and Intelligence (1989). He was an authority on the problem of strategic surprise and on the methodology and theoretical aspects of intelligence. His interests included the future of naval warfare and the role of navies in interventions. At the time of his death, he was working on a book on multi-front warfare, and on studies of comparative strategic theory.

Clausewitz's seminal work, On War, may not be easy to read, but it is also not as difficult as many assume at first glance. The interested reader must, however, be willing to invest considerable time in the study of this text. This is not a book that can or must be understood upon a first reading; some passages or sections of the book are obscure and susceptible to more than one interpretation, while others require concentration, repeated reading (particularly Book 1, Chapter 1), and classroom analysis. Indeed, part of the professional military value of reading On War is that it forces the reader to ponder Clausewitz's ideas. By engaging in this rewarding process, the reader develops his own concepts and emerges with more profound insights into the various aspects of warfare.

On War should not, however, be treated as though its classic nature has rendered it virtually immune to criticism. Like all works of such stature, it will always be a source of many eternally relevant, original thoughts on warfare—but at the same time, it includes some ideas that were debatable from the beginning, and still others that became obsolete as a result of subsequent technological and political developments.

Apparent contradictions in the text should not cause the reader undue concern. In the first place, war's intrinsically human underpinnings mean that it is indeed fraught with unavoidable, genuine contradictions such as that between the principle of continuity and the concept of the culminating point of victory (or the attack). The former principle suggests the need to exploit a victory to the utmost by continuing the offensive advance without interruption, while the latter states that continuing beyond a certain point in the offensive is counterproductive and brings defeat. (See M. Handel, Masters of War, 2nd rev. and expanded edition, Chapter 11, pp. 99-120.) This type of contradiction between two concepts in war can only be addressed by examining the specific circumstances in each case.

Other contradictions are only apparent and can be explained, for example, by the different levels of analysis in question. (See Handel, Masters of War, Appendix A, "Contradiction and Paradox in the Theory of War," pp. 181-183.) Thus, Clausewitz frequently states that most intelligence is unreliable while elsewhere, he observes that it can sometimes be reliable. This is not a genuine contradiction because most of his comments on intelligence refer to the lower tactical and operational levels where the the heat of battle and pressure of time often render intelligence unreliable even today. His positive remarks on this subject, however, refer to the strategic level, where there is more time to verify movement and other types of information.

Since war is not an exact science, Clausewitz is also careful to note exceptions when he makes an observation or recommendation. Therefore, the identification of such so-called flaws in On War actually enhances one's understanding of war as a human and social phenomenon. Furthermore, any theoretical work of this type that is devoid of apparent or real contradictions could never represent a realistic analysis of the real world of war.

The reader must also remember that this guide addresses On Waras it stands and is not therefore concerned with the intellectual process, the so-called "transformation of ideas," through which Clausewitz arrived at the final text.


My first recommendation is that the reader begin On War NOT with Book 1 Chapter 1, but with Book 2 Chapter 2, "On the Theory of War," in particular pp. 136-141 and pp. 146-147. In this very "modern" chapter (still relevant to anyone studying the social sciences), Clausewitz lays the methodological foundation for the entire book. He argues that given human nature, war cannot be studied as though it is an exact science (what he calls a "positive doctrine"). In fact, he concludes that war is neither an art nor a science but "an act of human intercourse" or what we would call today a social science (pp 148-149). Therefore, the student of war and military affairs should not expect to receive specific guidance for action from books such as On War. On War is not an instruction manual, nor can there be such a book for the highest levels of studying war (i.e., policy, strategy, or even the operational level). Although war can be studied systematically, it is ultimately an art that requires creative (not dogmatic) solutions reflecting specific or unique situations.

Next the student should read Chapters 5 and 6 of Book 2 ("Critical Analysis" and "On Historical Examples"). These chapters further expand some of the ideas developed in Chapter 2 and discuss the very methods used to teach in the Department of Strategy and Policy of the Naval War College, namely the extensive use of the critical analysis of historical case studies.

Finally, remember that it is not necessary to understand all of the finer details of Clausewitz's argument, but rather to think critically about the lessons taught by military history. Why is there no substitute for the detailed examination of past wars? How is past experience relevant and what are its limitations? (Each historical case has many unique aspects which will never be repeated in precisely the same way.) What, for example, is the impact of technological change on the value of the historical case study method?


Now you are ready to begin reading Chapter 1 of Book 1, which is the most important chapter of the entire book. First of all, it contains the essence of most of Clausewitz's original ideas and establishes the framework for the entire book. Second, it is the only chapter he edited in final form before his death. Unfortunately this also happens to be the most difficult chapter in the book! Ideally, this chapter should be read more than once, for it cannot be fully understood in a single reading. Each reading of this chapter, which is infinitely rich with ideas, gives the student a new "layer" of understanding. Indeed, had Clausewitz written only this chapter and nothing else, his place as the most important theorist of war would still remain unchallenged. (Refer to the folded chart at the end of this booklet for a "flow chart" of Clausewitz' ideas and discussion in Chapter 1.)

Here are a number of specific suggestions:

Clausewitz's opening statement of Book 1, Chapter 1, Section 1 of On War, makes it clear right from the start why war cannot be studied as an exact science. "...In war," he states, "more than in any other subject we must begin by looking at the nature of the whole; for here more than elsewhere the part and the whole must always be thought of together," (i.e. unlike in the natural sciences, different variables or factors cannot be isolated and studied independently.) The parts can only be studied in the context of the whole, as a "gestalt." (He refers to war as a gestalt also among others on pp. 61, 63, 77; 137; 158; 183).

Chapter 1, Section 2, p. 75: Think about his brief definition of war. Why is it so important, and what does it tell us about the purpose of all wars?

Note that the definition of war implies the survival rather than the total destruction of the enemy. Also note that what distinguishes war from any other activity is the use of force and bloodshed. This definition must be read along with another definition of war presented in Book 2, Chapter 3: "War is a clash between major interests, which is resolved by bloodshed-that is the only way in which it differs from other conflicts" (p. 149). Elsewhere, Clausewitz offers yet another definition: "Essentially, war is fighting, for fighting is the only effective principle in the manifold activities generally designated as war" (p.127).

Acknowledging the general tendency to disregard international law and custom, Clausewitz not only sees war as inevitable but also as a common and legitimate instrument states must sometimes use to protect their vital interests.

Chapter 1, Sections 3-5, pp. 75-77: Here Clausewitz discusses war not as it is in reality, but as it is in theory, in the "abstract." He refers to war in the abstract or what war should logically be as "absolute war," "war in theory," "war in pure theory," "the natural tendency of war," "play of imagination," or "the strict law of inherent necessity." Here he uses a well-known technique from the social sciences called the ideal-type method in which the writer distills the essential characteristics of a social phenomenon from its "messier" reality.

Most of the value derived from the ideal-type method, though, comes from comparing the ideal version with reality and then asking how and why the two differ. Clausewitz engages in these "modifications in practice," as he calls them, for the rest of the chapter (i.e., Sections 6-23). (See chart on p.3). (Also note that in the folded flow chart, the sections of Chapter 1 discussing war in the abstract or the ideal type are marked in black).


Illustration:War in Theory and In Reality Compared

By asking why war in practice differs from war in theory (from what it logically ought to be) Clausewitz develops his most important ideas about war! (This is very similar to the Newtonian method of first discussing the laws of physics in a simplified, frictionless world and later adjusting the theory to a world of friction,or to the economists' reference to a perfectly free market). As a careful reading will show, this method leads Clausewitz to develop such concepts as friction and uncertainty in war; the rational (i.e., political) direction of war; and the differences (or asymmetry) between the offense and defense, total and limited war, and so on.

As you read this chapter (and the rest of the book), it is important not to confuse the ideal-type of war (i.e., war in the abstract, war in theory, a pure concept of war, etc. ) with real war (or war in practice). In most instances Clausewitz tells the reader what type of war he is discussing, but not always.

Let me begin with Clausewitz's description of war in theory. In Sections 3 to 5, Clausewitz identifies three inherent types of interaction in war that in theory (and sometimes in practice) lead to an escalation to the extreme. These are:

1. The Maximum Use of Force. (Physical force). In order to be assured of victory, the opponents will theoretically employ all available force against each other. This first case of interaction is directly related to other principles developed later in On War such as the maximum concentration of forces in space and time, and the importance of achieving numerical superiority in battle (see Book 3, Chapters 8, 11, 12, and 14, and Book 5, Chapter 12). This is a good example of how Clausewitz's concepts and description of the ideal-type of war in theory are, later in the book, applied to war in reality.

2. The Aim Is To Disarm The Enemy. (The objective of war; or war as a zero-sum game) The second case of interaction is closely connected to the first. It states that each side will continue fighting until its enemy has been disarmed and is no longer a threat. (The second case of interaction is also closely related to the principle of continuity, see p. 7. Clausewitz returns to this theme in Chapter 2 of Book 1, see p. 91.)

3. The Maximum Exertion of Strength. (Intangible factors; or non-material force multipliers, or what he refers to as "moral forces") The third case of interaction suggests that in addition to mobilizing and using all possible physical/material force, the opponents simultaneously marshall all of the moral and spiritual forces available (e.g., motivation, dedication, and spirit of sacrifice). In contrast to the physical forces, which are relatively easy to estimate, the equally important moral forces are more difficult to gauge. When one side has reached the limits of its material strength, it can always add to its military efforts by mobilizing all possible moral strength. Moral forces thus act as a force multiplier, making estimates and net assessment far more complex. The balance of power must therefore be estimated (in Clausewitz's own words) as follows:



Throughout On War, Clausewitz returns to the discussion of moral forces (e.g., will, motivation, creative genius, intuition, patriotism and all other non-tangible factors that affect the course of a war). (See, for example, Book 1, Chapter 3, pp. 136-138); Book 2, Chapter 2, pp. 136-137 Book 3, Chapters 3 and 4, pp. 184-186).

For the remainder of the chapter Clausewitz explains why the extreme nature of war in theory is moderated in reality by factors such as political (rational) calculations; the inability to use all forces at once; the difference in strength between the offense and defense; insufficient or inaccurate intelligence on the relative strength of the opponent; and aversion to risk or other psychological considerations. (See discussion below.)

In Chapter 1, Clausewitz tacitly introduces a comprehensive framework for the study of war. (Section 5, p.77) Here he argues that war always includes rational and non-rational elements, physical (or material) and moral (or spiritual, non- material) factors, planning, and control, as well as uncertainty, friction, and chance. Such a framework is eternal because all of these complementary and at times seemingly contradictory elements deal with every dimension of warfare.



This framework is succinctly and elegantly summarized in his famous "trinity" (Chapter 1, Book 1, Section 28, p. 89) in which the passions, (people); probability and chance, (military); and objectives, and rational calculations, (government) can form countless unique combinations reflecting the character of each war.V

Note that Clausewitz's framework for the study of war and his analysis throughout the book fully recognizes the importance of non-rational (as well as rational) factors such as the charisma, creativity, and coup d'oeil of the military leader; the morale and motivation of the people; the influence of danger and battle on the ability to make rational calculations under pressure; and the effect of uncertainty, friction, chance, and insufficient information/intelligence on the ability to make rational calculations. I mention this because John Keegan, in his most recent book A History of Warfare (New York: Knopf, 1993), erroneously states that Clausewitz's approach to war is entirely or primarily based on rational calculations. This is plainly wrong. (For an explicit statement on the impossibility of conducting war as a purely rational activity, see Book 8, Chapter 2, p.579.)

When reading Chapter 1 of Book 1 also consider: How or why does politics modify war in theory by emphasizing the rational (instrumental) purpose of war (as already indicated in his definition of war)? (Remember that in war in theory the maximum use of force is not based on rational calculations but on the inherent dynamic nature of interaction.) Devote some time to thinking about Section 27 (p. 88), the second paragraph, where he stresses the importance of understanding the nature of the war a nation is about to get involved in. (See discussion below pp.11-12.) How does the question of the kind of war (Section 27) relate to the following section (Section 28), the trinity (or triad) and the observation that war is "like a chameleon?" (Note that Clausewitz's comparison of the mercurial nature of war to a chameleon is analogous to Sun Tzu's comparison of war to water." "And as water has no constant form, there are in war no constant conditions." (Sun Tzu The Art of War, Chapter 6, p.101.) We will return to this question throughout the course. Section 27 (on the importance of understanding the diverse nature of war) and Section 28 in which Clausewitz develops his "trinitarian analysis" are closely related, as the "trinitarian analysis" establishes the most important elements in defining or describing the diverse nature of each war. (See p.10 below.)


How does Clausewitz move from war in theory to war in practice? How does he show that in reality, war rarely follows the dialectics of the extreme? (In Book 7, Chapter 1, Clausewitz explains the dialectical method as he sees it: "...Where two ideas form a true logical antithesis, each complementary to the other, then fundamentally each is implied in the other. If the limitations of our mind do not allow us to comprehend both simultaneously, and discover by antithesis the whole of one in the whole of the other, each will nevertheless shed enough light on the other to clarify many of its details.") (p. 523). (This is similar to the idea of yin and yang.)

In Section 6, Clausewitz begins by discussing the necessity of a correct transition from the theoretical world to the real world. In Section 7, he observes that since the enemy is not a total unknown in most cases, a state does not have to use all of its forces (as noted in the first case of interaction) but only the amount needed to do the job. Next he reasons that even if one could use all of the forces at his disposal, such forces could never realistically be concentrated in one place at one time (Section 8).

Section 9 is one of the shortest—and most important in the book. It states that even if one side achieves a military victory, such a victory is rarely final. This is because the defeated enemy who does not accept the result will simply wait for a better time to fight again. Consequently, the maximum use of military force is only a necessary but not sufficient condition for final victory; diplomacy and political wisdom are the "missing ingredients" needed to consolidate the results achieved in battle. In reality, therefore, it is wiser to rely on the combination of adequate strength and diplomacy. Through the modifications of war in theory as outlined in Sections 7, 8, and 9, the reader is able to follow Clausewitz's transition from a war of absolutes to his analysis of war in reality in Section 10.

In Section 11, Clausewitz reintroduces the political objective in war: If the absolute war is confined to the realm of theory, what actually determines the use of force in war? The political authorities (not the inherent dynamics of war) determine what the objectives are, and what achieving a given objective is worth in terms of the military resources to be invested. This, in turn, determines how much counterforce the enemy will have to employ. Accordingly, war is not just one uncontrolled clash of all forces available as the three cases of interaction imply; instead, it is a calculated political decision that can range from the extreme use of force to minor engagements. The analysis of war in reality (or in practice) in Chapter 1 thus clearly implies the existence and logic of limited war. (Clausewitz again defines the role of politics in war in Section 23, 24, 25 and 26. See also Book 8 in particular Chapters 6A and 6B where he further develops the same ideas.)

At this point, Clausewitz introduces an ideal-type concept - the principle of continuity. According to the principle of continuity (Sections 12-14), war in theory is fought without interruption until one of the sides is victorious. The reasoning is as follows: If one side has achieved an advantage he must or should exploit it until he wins (i.e., disarms the enemy (Section 4) and compels the enemy to do his will (Section 2)). In Sections 13 and 14, Clausewitz—in one of the most complicated discussions in On War—explains why war is frequently interrupted despite the logic of the principle of continuity. This leads him to an analysis of the differences in nature and strength between the offense and defense (Sections 15-17), and a discussion of how war is interrupted because of poor intelligence and the commander's tendency to make worst-case assumptions (Section 17). The asymmetry or inherent differences of the offense and defense combined with poor intelligence thus explain why the principle of continuity is ignored in reality. (For a detailed discussion, see Chapter 11 of the second revised edition of Masters of War by Handel.) Inaction in war, which is common in practice but makes no sense in theory, thus further removes war from its absolute, theoretical form. Later in On War, Clausewitz expands on the practical consequences of inaction in war. (See Book 3, Chapter 16, pp. 216-219; and the second paragraph of Book 3, Chapter 2, p. 579.)

In Section 19 Clausewitz repeats his argument that war is a probabilistic affair. This, in turn, means that it always involves taking chances (Section 20) and therefore, is also always a gamble that requires courage (Section 21), an environment in which many military leaders feel more comfortable (Section 22). (He returns to this subject in Chapter 2 of Book 1, see p. 91.)

In Sections 23, 24, 25, and 26, Clausewitz introduces the political/policy factor for the second time. This is the most important factor in modifying the absolute nature of war; that is inherent theoretical tendency to escalate to the extreme as discussed in Sections 3, 4, and 5. Politics and policy determine the objectives of war—that is, the degree to which the state or group is ready to invest in achieving these ends. Political calculations introduce the rational calculation of ends and means, costs and benefits. (See also Book 1, Chapter 2, pp. 90-92. Clausewitz adds to his discussion of politics and policy in Book 8, particularly in Chapters 6, parts A and B (On War, pp. 603-610). These must be read in conjunction with Section 23-26 of Book 1, Chapter 1, pp. 86-88.) (Clausewitz in the tradition of raison d'etat assumes that the leaders of the state pursue a policy of enhancing the vital interests of the state (i.e. of its power vis-…-vis other states). He does not discuss the possibility that some leaders (e.g., Napoleon or Hitler) can pursue either personal or non rational goals. (But see his comments on the formation of policy in Book 8, Chapter 6B, pp. 606-607.)

In Section 25, Clausewitz argues that the higher the stakes in war and the more important the political stakes - the more violent war will tend to become; therefore it will also tend to approximate absolute war. (In Chapter 2 of Book 8 he in fact suggests that war in his time has come close to resembling the absolute war in theory, " might wonder "he says" whether there is any truth at all in our concept of the absolute character of war were it not for the fact that with our own eyes we have seen warfare achieve this state of absolute perfection," p.580.) (See also pp 593, 603 and 610.) Conversely the more moderate or limited the political goals, the more war is removed from the ideal type of absolute war. The more violent a war becomes, the greater the chances that the political leaders will lose control over the course of the war as the passions of the belligerents and the war's own momentum take over. (As the ideal type of absolute war suggests.) This may create the impression that the more violent wars are less political than limited wars, but this is not really the case (i.e. all wars, whether total or limited, are equally political.)

Clausewitz rounds out the already rich and varied discussion in Chapter 1 with the introduction of two additional interrelated concepts. The first, introduced in Section 27, is the need to understand the nature of war before embarking upon it; and the second, in Section 28, is his famous "trinitarian analysis." The first simply suggests that no two wars are ever the same: the participants, their respective morales, motivations, strategies, military doctrines, and weapons technologies change from one occasion to another and even in the course of a single war. The statesman and strategist must therefore attempt to understand the unique character of each war. Is it to be short or long, conventional or low- intensity, hi-tech or low tech? How will the enemy react to his contemplated strategy? Such in-depth analysis is not an easy requirement since the interaction of two opponents in war is not a "linear" or predictable process. Note that there is substantial tension between Clausewitz's advice that one should attempt to grasp the nature of a future war on the one hand, and his emphasis on the problems of forecasting in a world rife with friction, uncertainty, chance, and lack of intelligence on the other. Rapid technological changes in modern weapon technology have made understanding the nature of war even more difficult than in Clausewitz's time.

In the last section (28) of Chapter 1, Clausewitz introduces a conceptual framework that makes it easier to understand the nature of each war. Clausewitz argues that the behavior of each nation and its capacity to wage war depend on three groups of factors: the people, the military, and the government. When considering the people, one must examine, for example, their motivation, dedication, and support of their government. Of the military, one should ask how good their leaders are, whether they obey government orders, and whether they develop suitable doctrines and are well organized. And as for the government, it is wise to investigate how rational or realistic its policies are, and how effective it would be in mobilizing the people's support for a prolonged war. The three elements of the trinity - the people, the military, and the government - represent, or are an abbreviated code for, the tendencies underlined above. It must also be emphasized that these tendencies are not exclusive only to the people, the military, and the government and may in certain circumstances be better represented by other elements (e.g., at times the military or the "people" may be more rational and calculating than the political leadership).

The interrelationship of these three factors or "three aspects" of war will determine the way in which each country wages war. Think, for example, of the Vietnam War: Did the U.S. government define clear objectives for the war? Did it effectively mobilize the support of the American people? Did the U.S. military develop a suitable doctrine? Was the doctrine effectively adapted to changing circumstances on the battlefield? Was the government given the best possible advice by the military? Was the U.S. population united in its support of the government and for how long?

Comparing these three main factors for each participant in a war allows the strategist to make a more reliable forecast. For instance, in the Vietnam War, which population was more dedicated and ready to act? Which military was more adaptable and responsive to developments on the battlefield? The relationship among the three components of "the trinity" is dynamic and different in various types of war (i.e., the role of the people is relatively more important in guerrilla warfare than in conventional, hi-tech war).

"The trinity" includes only "non-material" or non- tangible factors, such as policy, organization, and motivation— and ignores war's material, technological, and economic dimensions. Clausewitz might have concluded that the material dimensions were not necessary for understanding the nature of war, or that they were a roughly comparable "given" for each belligerent. In any case, it is possible to criticize Clausewitz's approach with the observation that he does not pay enough attention to the material aspects of war. (On this, see Michael Handel, "Clausewitz in the Age of Technology," in Michael Handel, ed., Clausewitz and Modern Strategy (London: Cass: 1986), pp. 51-94.)


It must be noted that Clausewitz believed that the most important changes in war at this time were all political not natural. "...These changes were caused by the new political conditions which the French Revolution created both in France and Europe as a whole, conditions that set in motion new means and new forces...the transformation of the art of war resulted from the transformation of politics" (p.610; also p.593).

It is the interaction between all the "trinities" of the belligerents that defines the particular nature of each war.

Try not to become discouraged if you do not understand everything in Chapter 1. Finish reading the rest of the assigned chapters and then come back to Chapter 1 and read it again (and again if necessary). This chapter will be discussed in detail in the seminar later on.

Before finishing your work on Chapter 1, read Section 9 ("In War the Result is Never Final," p. 80) one more time. What is the importance of this statement? How does this fact influence the need to consider the question of war termination throughout the war? What does it suggest about the correct relationship between the political and military authorities?

Once you leave Chapter 1, you are on the open road. The rest of the chapters in the book are much easier!

Chapter 2 of Book 1 (pp. 90-99) is devoted to a number of important issues, the first of which is the problem of war termination. According to Clausewitz, wars are brought to an end for three possible reasons: (1) the inability to carry on the struggle (i.e. defeat); (2) the improbability of victory; and (3) unacceptable cost. Here he introduces what I call the rational calculus of war termination: "Since war is not an act of senseless passion but is controlled by its political object, the value of this object must determine the sacrifices to be made for it in magnitude and also in duration. Once the expenditure of effort exceeds the value of the political object, the object must be renounced and peace must follow" (p.92).

Note that while such rational calculations make sense in theory—they are very different to implement in reality. Why is this invariably the case? Clausewitz's emphasis on the need to wage war as rationally as possible must be viewed as a normative recommendation - not as a description of reality. As we have seen in the above discussion, he is fully aware of the limits of rational analysis in war. He knows that the hatreds, passions, emotions, and costs incurred in the process of waging war may at times render a rational decision making process extremely difficult if not impossible. The discussion of the rational calculus of war termination is immediately followed by an "equilibrium analysis" considering the motivation of each of the belligerents to initiate negotiations for war termination (p.92).

The final pages of Chapter 2 (pp. 96-97) begin by introducing the principle of destruction which suggests that all other things being equal "The destruction of the enemy forces is always the superior, more effective means, with which others cannot compete." It must, however, be made clear that the destruction of the enemy forces is not necessarily physical but can be moral or psychological. "When we speak of destroying the enemy's forces we must emphasize that nothing obliges us to limit this idea to physical forces: the moral element must also be considered" (p.92). Furthermore even the actual destruction of the enemy's forces is not always required. "Combats'. . . . . aim is to destroy the enemy's forces as a means to a further end. That holds true even if no actual fighting occurs, because the outcome rests on the assumption that if it came to fighting the enemy would be destroyed" (p.97, also, p.181). These statements are very much in agreement with Sun Tzu's approach to the art of war. Yet the final pages of the chapter (pp. 97-99) include a truly outstanding argument (which so far has received very little attention!) against Sun Tzu's idea that the best way to win a war is without fighting. That which is the ideal achievement and epitome of success in war for Sun Tzu - is an exception for Clausewitz. (See Michael Handel, Masters of War, Chapter 9). (On the destruction of the enemy forces, see also Chapters 3, 4 and 11 of Book 4.)

Chapter 3 of Book 1 is one of the longest in the book. Since war is not a science, but an art, and therefore requires innate talent and genius, Clausewitz now discusses the necessary characteristics of the military genius (the military commander as an artist, if you wish). Note however that most of the qualities he considers are those required for battle on the operational not the strategic level (but see his comments on the need to understand strategy and policy on p. 111).

The qualities that Clausewitz admires in the military genius are above all self- confidence, trust in his experience and intuition (his coup d'oeil), the ability even in the heat of battle to stick confidently to his original goal (the "imperative principle," p.108). While he must "stand like a rock" (p.117) amidst the turmoil of battle, his maintenance of aim should not deteriorate into obstinacy. Above all, Clausewitz identifies great military leadership with the readiness to take risks. (See also Chapter 6 of Book 3).

The remaining chapters in Book 1 are important but require no particular explanation.


When Clausewitz talks about strategy, he is actually discussing what we would now consider to be the operational level. (See Chapter 1 of Book 3 for his definition of strategy.) Note that the first section on p. 181 on possible engagements brings him closer to some of Sun Tzu's arguments.

Chapter 8 of Book 3 addresses the role of moral factors in war. (Compare it with Book 2, Chapter 2, pp. 136-137.)

Chapter 8 of Book 3 discusses the importance of numerical superiority and should be read together with Chapter 3 of Book 5, pp. 282-284. Chapters 9 and 10 of Book 3 are on surprise and deception. This is where Clausewitz differs the most from Sun Tzu. (See Handel, Masters of War, Chapter 11.)

Chapter 11 of Book 3 on "the concentration of forces in space" is short but notable as one of the few general "principles of war" offered by Clausewitz. (See also Book 3 Chapter 8.)

Chapter 16 of Book 3, "The Suspension of Action in War," should be compared and read together with Sections 14, 16, and 17 of Book 1, Chapter 1.

Chapter 17 of Book 3 is important as a reference to the new character of war in Clausewitz's own time which influenced his theory of war. (See also Chapter 16, pp. 218-219.)


Chapters 2 and 4 of Book 4 are also dedicated to the study of the new character of war as established by the wars of the French Revolution. The chapters discussing the nature of modern war therefore provide the general background/context for his observations on war. Chapters 4 and 11 also provide ideas for a possible comparison with Sun Tzu.

The greatly increased intensity of warfare since the wars of the French Revolution and Napoleon brought war in reality much closer to Clausewitz's description of war in theory (the absolute war). (See also, Book 8, Chapter 2, p.580). Chapters 3 and 4 of Book 4 discuss the definition of victory and the need under most circumstances to destroy the enemy's forces in order to achieve victory. In Chapter 4, Clausewitz discusses the connection between physical and moral factors in victory (or defeat). Chapter 11 of Book 4 must be read with Sun Tzu in mind. Here Clausewitz argues that winning without battle is "nonsense." Is he right? Was he right for his own time? How does this relate to some of his other statements? Is he consistent?


Book 5, on military forces, is of much less interest to the strategist as it is primarily concerned with tactical and operational questions. But read Chapter 3 on relative strength. Compare it with Chapter 8 of Book 3.


In Book 6, read Chapter 1 for a general statement on the nature of the defense. Read Chapter 5 and Chapter 23 entitled, "The Key to the Country," and compare them with the discussion in Chapter 27, on the concept of the center of gravity. (Chapter 27 is entitled "Defense of a Theater of War.") The same question is also discussed in Chapter 4 of Book 8. (See also Handel, Masters of War, Chapter 5). Perhaps the most critical, and certainly one of the most interesting chapters in Book 6 is Chapter 26, "The People in Arms," which is an excellent summary of the unique character of guerilla warfare. Most of the insights and principles of guerrilla warfare (people's war) later developed at great length by Mao Tse Tung, can be found in essence in Chapter 26 of Book 6 a century before.


Book 7 is dedicated to the attack. Begin by reading Chapter 2 which, among other issues, discusses the concept of the culminating point of the attack (namely, that every offensive ultimately exhausts itself and cannot go on indefinitely). The attacker must know when to move over to the defense and consolidate his gains while he has the advantage. This theme also dominates Chapters 3, 4, 5, and 22.

While this concept is of great interest analytically, it does not provide the strategist or field commander with any concrete advice. Like most of the other concepts Clausewitz develops, it makes the reader think and ask further questions, but does not give him any "practical" answers. Consider the concept of the center of gravity in the same way. How useful is such a "mechanical" concept? What is the value of this concept? (See Chapter 11 of the second revised edition of Handel's Masters of War.)


In Book 8, Clausewitz returns once again to his discussion of the highest political and strategic levels of war (and to many of the concepts introduced in Chapter 1). Above all, pay attention throughout Book 8 to the tension between the desire to wage war as rationally as possible—to see war as a carefully calculated affair—and the need to consider the limits on rational calculations. Also note the tension between the inherent trends in war toward the extreme (toward the absolute war) and the moderating influence of rational political calculations on limiting war. Chapter 3B includes an interesting discussion of the evolution of war in historical perspective in different societies (see pp. 586-594). The most important statement on the political nature and the political control of war is to be found in Chapter 6B, "War as an Instrument of Policy." This is perhaps the most crucial chapter in the book. Read the rest of Book 8. Chapter 6 of Book 8 includes an elegant definition of policy: "It can be taken as agreed that the aim of policy is to unify and reconcile all aspects of internal administration as well as of spiritual values, and whatever else the moral philosopher may care to add. Policy, of course, is nothing in itself; it is simply the trustee for all these interests against other states. That it can err, subserve the ambition, private interests, and vanity of those in power, is neither here nor there. In no sense can the art of war ever be regarded as the preceptor of policy, and here we can only treat policy as representative of all interests of the community (pp. 606-607).

When Clausewitz started his work on On War he saw the absolute war with its tendency to escalate and search for definite clear-cut results as the only possible way to wage war. At a later stage (1827) he came to recognize that not all wars are or will be waged in that way, and that the political nature of war introduces a moderating influence that makes limited wars not only possible but likely. After recognizing this "dual nature of war," he decided to write Book 8 and rewrite the entire book (we know for certain that he rewrote Chapter 1 of Book 1 and possibly Chapter 2 of Book 1).

If we ignore this transformation of Clausewitz's ideas and read On War as it now stands, it is clear that he fully recognized the dual nature of war in Book 1 as well as Book 8 and also Book 7, chapter 16.


Recently, some critics have pronounced Clausewitz's On War irrelevant for pre-modern and modern warfare. But while On War should be read critically and does contain some dimensions that are obsolete - most of his ideas, analytical concepts, and discussions on war are valid and useful. Friction, chance, uncertainty, or moral factors will always influence war and conflict; the "trinitarian analysis" is relevant for all types of war in every era; and his emphasis on the political nature of war is critical as both a factual and normative statement.

Clausewitz warns the reader "war is no pastime ... it is a serious means to a serious end.... (On War, Book 1, Section 23, p.86). In The Transformation of War by Martin Van Creveld, one encounters a curious statement discounting the political nature of war; namely, "war is the continuation of sport by other means." Such assertions cannot be taken seriously anywhere—and certainly not in a democracy.

Clausewitz's On War is a challenge to all professional military officers, military experts, and strategists. Once you have "deciphered" Chapter 1 of Book 1, it is much easier going. Like all challenges, this one requires a considerable effort but in the end is well worth the investment. Although a "theoretical" work, On War is in fact of immense practical value for policy makers, strategists and military commanders at the higher operational level. Although it does not give the reader concrete, manual-like answers, it offers him insights that no other book can match into the problems of waging war on the highest level.

The following works can help the reader to deepen his understanding of On War:

Michael I. Handel, (ed.), Clausewitz and Modern Strategy (London: Cass, 1989). The introduction, pp.1- 10 and Michael I. Handel, Masters of War, Second Revised and expanded edition (London: Cass, 1996). This book, referred to in my comments above, will be given out to you at the beginning of the course. Or Michael I. Handel Masters of War (second revised and inlaid edition) (London: Cass 1995) if available. (Includes a bibliography of works on Clausewitz in English.)


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