On War

by Clausewitz


…War is nothing but a duel on an extensive scale... an act of violence to compel our opponent to fulfill our will.

Violence arms itself with the inventions of art and science in order to contend against violence. Self-imposed restrictions, almost imperceptible and hardly worth mentioning, termed usages of International Law, accompany it without essentially impairing its power. Violence, that is to say physical force (for there is no moral force without the conception of states and law), is therefore the means; the compulsory submission of the enemy to our will is the ultimate object. In order to attain this object fully, the enemy must be disarmed; and this is, correctly speaking, the real aim of hostilities in theory...

Now, philanthropists may easily imagine there is a skillful method of disarming and overcoming an enemy without causing great bloodshed, and that this is the proper tendency of the art of war. However plausible this may appear, still it is an error that must be extirpated; for in such dangerous things as war, the errors that proceed from a spirit of benevolence are just the worst. As the use of physical power to the utmost extent by no means excludes the cooperation of the intelligence, it follows that he who uses force unsparingly, without reference to the quantity of bloodshed, must obtain a superiority if his adversary does not act likewise…

This is the way in which the matter must be viewed; and it is to no purpose, and even acting against one's own interest, to turn away from the consideration of the real nature of the affair, because the coarseness of its elements excites repugnance.

If the wars of civilized people are less cruel and destructive than those of savages, the difference arises from the social condition both of states in themselves and in their relations to each other. Out of this social condition and its relations war arises, and by it war is subjected to conditions, is controlled and modified. But these things do not belong to war itself; they are only given conditions; and to introduce into the philosophy of war itself a principle of moderation would be an absurdity.

… Amongst savages views emanating from the feelings, amongst civilized nations those emanating from the understanding, have the predominance; but this difference is not inherent in a state of barbarism and in a state of culture in themselves, it arises from attendant circumstances, existing institutions, etc., and therefore is not to be found necessarily in all cases, although it prevails in the majority. In short, even the most civilized nations may burn with passionate hatred of each other.

…If war is an act of force, it belongs necessarily also to the feelings. If it does not originate in the feelings, it reacts more or less upon them, and this more or less depends not on the degree of civilization, but upon the importance and duration of the interests involved.

Therefore, if we find civilized nations do not put their prisoners to death, do not devastate towns and countries, this is because their intelligence exercises greater influence on their mode of carrying on war, and has taught them more effectual means of applying force than these rude acts of mere instinct. The invention of gunpowder, the constant progress of improvements in the construction of firearms are sufficient proofs that the tendency to destroy the adversary which lies at the bottom of the conception of war, is in no way changed or modified through the progress of civilization.

...If we desire to defeat the enemy, we must proportion our efforts to his powers of resistance. This is expressed by the product of two factors that cannot be separated -- namely, the sum of available means and the strength of the will….



… Reasoning in the abstract, the mind cannot stop short of an extreme…but everything takes a different form when we pass from abstractions to reality. In [abstractions] everything must be subject to optimism, and we must imagine the one side as well as the other, striving after perfection and even attaining it. Will this ever take place in reality? It will if

1) War becomes a completely isolated act, which arises suddenly and is in no way connected with the previous history of the states;
2) If it is limited to a single solution, or to several simultaneous solutions;
3) If it contains within itself the solution perfect and complete, free from any reaction upon it, through a calculation beforehand of the political situation which will follow from it.

But…war is never an isolated act…It does not consist of a single instantaneous blow…The result in war is never absolute… even the final decision of a whole war is not always to be regarded as absolute. The conquered state often sees in it only a passing evil, which may be repaired in after times by means of political combinations. How much this also must modify the degree of tension and the vigor of the efforts made is evident in itself.

…The law of the extreme, the view to disarm the adversary, to overthrow him, has hitherto to a certain extent usurped the place of [the political] end or object... If the whole consideration is a calculation of probability based on definite persons and relations, then the political object, being the original motive, must be an essential factor in the product. The smaller the sacrifice we demand from our opponent, the smaller it may be expected will be the means of resistance which he will employ; but the smaller his are, the smaller will be required of us. Further, the smaller our political object, the less value shall we set upon it, and the more easily shall we be induced to give it up altogether.

...[T]he political object, as the original motive of the war, will be the standard for determining both the aim of the military force, and also the amount of effort to be made. This it cannot be in itself; but it is so in relation to both the belligerent states, because we are concerned with realities, not with mere abstractions. One and the same political object may produce totally different effects upon different people, or even upon the same people at different times; we can, therefore, only admit the political object as the measure, by considering it in its effects upon those masses which it is to move, and consequently the nature of those masses also comes into consideration. It is easy to see that thus the result may be very different according as these masses are animated with a spirit which will infuse vigor into the action or otherwise. It is quite possible for such a state of feeling to exist between two states that a very trifling political motive for war may produce an effect quite disproportionate, in fact, a perfect explosion...


We see from the foregoing how much the objective nature of war makes it a calculation of probabilities... There is no human affair which stands so constantly and so generally in close connection with chance as war. But along with chance, the accidental, and along with it good luck, occupy a great place in war.

If we now take a look at the subjective nature of war, that is, at those powers with which it is carried on, it will appear to us still more like a game. The element in which the operations of war are carried on is danger; but which of all the moral qualities is the first in danger? Courage.

...Theory must also take into account the human element; it must accord a place to courage, to boldness, even to rashness. The art of war has to deal with living and with moral forces; the consequence of which is that it can never attain the absolute and positive. There is therefore everywhere a margin for the accidental; and just as much in the greatest things as in the smallest. As there is room for this accidental on the one hand, so on the other there must be courage and self-reliance in proportion to the room left. If these qualities are forthcoming in a high degree, the margin left may likewise be great. Courage and self reliance are therefore principles quite essential to war; consequently theory must only set up such rules as allow ample scope for all degrees and varieties of these necessary and noblest of military virtues. In daring there may still be wisdom also, and prudence as well...


…The war of a community -- of whole nations and particularly of civilized nations -- always starts from a political condition, and is called forth by a political motive. It is therefore a political act. Now if it was a perfect, unrestrained and absolute expression of force, as we had to deduce it from its mere conception, then the moment it is called forth by political policy it would step into the place of politics, and as something quite independent of it would set it aside, and only follow its own laws…

But it is not so, and the idea is radically false. War in the real world, as we have already seen, is not an extreme thing which expends itself at one single discharge... but always lasting long enough to admit of influence being exerted on it in its course, so as to give it this or that direction, in short to be subject to the will of a guiding intelligence.

Now if we reflect that war has its root in a political object, then naturally this original motive that called it into existence should also continue the first and highest consideration in the conduct of it. Still the political object is no despotic lawgiver on that account; it must accommodate itself to the nature of the means, and through that is often completely changed, but it always remains that which has a prior right to consideration. Politics therefore is interwoven with the whole action of war, and must exercise a continuous influence upon it as far as the nature of the forces exploding in it will permit.

War is a mere continuation of politics by other means...We see, therefore, that war is not merely a political act, but also a real political instrument, a continuation of political commerce, a carrying out of the same by other means.… The political view is the object, war is the means, and the means must always include the object in our conception.

The greater and more powerful the motives of a war, the more it affects the whole existence of a people, the more violent the excitement which precedes the war, by so much the nearer will the war approach to its abstract form, so much the more will it be directed to the destruction of the enemy, so much nearer will the military and political ends coincide, so much more purely military and less political the war appears to be….

The weaker the motives and the tensions, so much less will the natural direction of the military element -- that is, force -- be coincident with the direction which the political element indicates; so much the more must therefore the war become diverted from its natural direction, the political object diverge from the aim of an ideal war, and the war appear to become political….[All acts of war] may all be regarded as political acts.

…Although it is true that in... [ideal] war the political element seems almost to disappear, whilst in another kind it occupies a very prominent place, we may still affirm that the one is as political as the other...

...[U]nder all circumstances war is to be regarded not as an independent thing, but as a political instrument; and it is only by taking this point of view that we can avoid finding ourselves in opposition to all military history. This is the only means of unlocking the great book and making it intelligible. Secondly, just this view shows us how wars must differ in character according to the nature of the motives and circumstances from which they proceed.

Now, the first, the grandest, and most decisive act of judgment which the statesman and general exercises is rightly to understand in this respect the war in which he engages, not to take it for something, or to wish to make of it something which, by the nature of its relations, it is impossible for it to be. …

War is, therefore, not only a true chameleon, because it changes its nature in some degree in each particular case, but it is also, as a whole, in relation to the predominant tendencies which are in it, a wonderful trinity, composed of the original violence of its elements, hatred and animosity, which may be looked upon as blind instinct; of the play of probabilities and chance, which make it a free activity of the soul; and of the subordinate nature of a political instrument, by which it belongs purely to the reason.

The first of these three phases concerns more the people; the second more the general and his army; the third more the Government. The passions which break forth in war must already have a latent existence in the peoples. The range which the display of courage and talents shall get in the realm of probabilities and of chance depends on the particular characteristics of the general and his army; but the political objects belong to the Government alone…



If we keep once more to the pure conception of war, then we must say that its political object properly lies out of its province, for if war is an act of violence to compel the enemy to fulfill our will, then in every case all depends on our overthrowing the enemy...

War does not, [however], always require to be fought out until one party is overthrown; and we may suppose that, when the motives and passions are slight, a weak probability will suffice to move that side to which [war] is unfavorable to give way. Now, were the other side convinced of this beforehand, it is natural that it would strive for this probability only, instead of first trying and making the detour of a total destruction of the enemy's army.

…As war is no act of blind passion, but is dominated over by the political object, therefore the value of that object determines the measure of the sacrifices by which it is to be purchased. This will be the case, not only as regards extent, but also as regards duration. As soon, therefore, as the required outlay becomes so great that the political object is no longer equal in value, the object must be given up, and peace will be the result.

…But now we come upon a peculiar means of influencing the probability of the result without destroying the enemy's army, namely, upon the expeditions which have a direct connection with political views. If there are any enterprises which are particularly likely to break up the enemy's alliances or make them inoperative, to gain new alliances for ourselves, to raise political powers in our own favor, etc., etc., then it is easy to conceive how much these may increase the probability of success, and become a shorter way towards our aim than the routing of the enemy's army.

…These are the circumstances in general connected with the aim that we have to pursue in war; let us now turn to the means.

There is only one single means, it is the Fight.

...Now, in the combat all the action is directed to the destruction of the enemy, or rather of his fighting powers, for this lies in the conception of combat. The destruction of the enemy's fighting power is, therefore, always the means to attain the object of the combat.

This object may likewise be the mere destruction of the enemy's armed force; but that is not by any means necessary, and it may be something quite different. Whenever...the defeat of the enemy is not the only means to attain the political object, whenever there are other objects which may be pursued, as the aim in a war, then it follows of itself that such other objects may become the object of particular acts of warfare, and, therefore, also the object of combats.

But even those combats which, as subordinate acts, are in the strict sense devoted to the destruction of the enemy's fighting force, need not have that destruction itself as their first object.…

Against the far superior worth which the destruction of the enemy's armed force has over all other means, stands the expense and risk of this means, and it is only to avoid these that any other means are taken...

Other methods are[...] less costly when they succeed, less dangerous when they fail; but in this is necessarily lodged the condition that they are only opposed to similar ones, that is, that the enemy acts on the same principle; for if the enemy should choose the way of a great decision by arms, our means must on that account be changed against our will, in order to correspond with his…

...The bloody solution of the crisis, the effort for the destruction of the enemy's force, is the firstborn son of war. If when political objects are unimportant, motives weak, the excitement of forces small, a cautious commander tries in all kinds of ways, without great crises and bloody solutions, to twist himself skillfully into a peace through the characteristic weaknesses of his enemy in the field and in the Cabinet, we have no right to find fault with him, if the premises on which he acts are well founded and justified by success; still we must require him to remember that he only travels on forbidden tracks, where the God of War may surprise him; that he ought always to keep his eye on the enemy, in order that he may not have to defend himself with a dress rapier if the enemy takes up a sharp sword…



Every special calling in life, if it is to be followed with success, requires peculiar qualifications of understanding and soul. Where these are of a high order, and manifest themselves by extraordinary achievements the mind to which they belong is termed genius.

…War is the province of danger, and therefore courage above all things is the first quality of a warrior.

Courage is of two kinds; first, physical courage, or courage in presence of danger to the person: and next, moral courage, or courage before responsibility; whether it be before the judgment seat of external authority, or of the inner power, the conscience...

Courage before danger to the person, again, is of two kinds. First, it may be indifference to danger, whether proceeding from the organism of the individual, contempt of death, or habit: in any of these cases it is to be regarded as a permanent condition. Secondly, courage may proceed from positive motives; such as personal pride, patriotism, and enthusiasm of any kind. In this case courage is not so much a normal condition as an impulse.

We may conceive that the two kinds act differently. The first kind is more certain, because it has become a second nature, never forsakes the man: the second often leads him further. In the first there is more of firmness, in the second of boldness. The first leaves the judgment cooler, the second raises its power at times, but often bewilders it. The two combined make up the most perfect kind of courage.

War is the province of physical exertion and suffering. In order not to be completely overcome by them, a certain strength of body and mind is required, which, either natural or acquired, produces indifference to them. With these qualifications under the guidance of simply a sound understanding, a man is at once a proper instrument for war; and these are the qualifications so generally to be met with amongst wild and half-civilized tribes.

If we go further in the demands which war makes on its votaries, then we find the powers of the understanding predominating. War is the province of uncertainty: three-fourths of those things upon which action in war must be calculated, are hidden more or less in the clouds of great uncertainty. Here, then, above all a fine and penetrating mind is called for, to grope out the truth by the tact of its judgment…

From this uncertainty of all intelligence and suppositions, this continual interposition of chance, the actor in war constantly finds things different to his expectations; and this cannot fail to have an influence on his plans… Now, if it is to get safely through this perpetual conflict with the unexpected, two qualities are indispensable: in the first place an understanding which, even in the midst of this intense obscurity, is not without some traces of inner light, which lead to the truth, and then the courage to follow this faint light...

Resolution is an act of courage in single instances, and if it becomes a characteristic trait, it is a habit of the mind. But here we do not mean courage in face of bodily danger, but in face of responsibility, therefore to a certain extent against moral danger. …We have assigned to resolution the office of removing the torments of doubt, and the dangers of delay, when there are no sufficient motives for guidance.

This resolution now, which overcomes the state of doubting, can only be called forth by the intellect and in fact by a peculiar tendency of the same. We maintain that the mere union of a superior understanding and the necessary feelings are not sufficient to make up resolution. There are persons who possess the keenest perception for the most difficult problems, who are also not fearful of responsibility, and yet in cases of difficulty cannot come to a resolution. Their courage and their sagacity operate independently of each other, do not give each other a hand, and on that account do not produce resolution as a result. The forerunner of resolution is an act of the mind making evident the necessity of venturing, and thus influencing the will. This quite peculiar direction of the mind, which conquers every other fear in man by the fear of wavering or doubting, is what makes up resolution in strong minds…

From the overall view and resolution, we are naturally led to speak of its kindred quality, presence of mind, which in a region of the unexpected like war must act a great part, for [war] is indeed nothing but a great conquest over the unexpected…If we take a general view of the four elements composing the atmosphere in which war moves, of danger, physical efforts, uncertainty, and chance, it is easy to conceive that a great force of mind and understanding are requisite to be able to make way with safety and success amongst such opposing elements, a force which, according to the different modifications arising out of circumstances, we find termed by military writers and annalists as energy, firmness, staunchness, strength of mind and character. All these manifestations of the heroic nature might be regarded as one and the same power of volition, modified according to circumstances; but nearly related as these things are to each other, still they are not one and the same...

As long as a troop full of good courage fights with zeal and spirit, it is seldom necessary for the chief to show great energy of purpose in the pursuit of his object. But, as soon as difficulties arise -- and that must always happen when great results are at stake -- then things no longer move on of themselves like a well-oiled machine, the machine itself then begins to offer resistance, and to overcome this, the commander must have a great force of will. By this resistance, we must not exactly suppose disobedience and murmurs, although these are frequent enough with particular individuals; it is the whole feeling of the dissolution of all physical and moral power, it is the heart-rending sight of the bloody sacrifice which the commander has to contend with in himself, and then, in all others who directly or indirectly transfer to him their impressions, feelings, anxieties and desires. As the forces in one individual after another become prostrated, and can no longer be excited and supported by an effort of his own will, the whole inertia of the mass gradually rests its weight on the will of the commander: by the spark in his breast, by the light of his spirit, the spark of purposes, the light of hope must be kindled afresh in others…

Of all the noble feelings which fill the human heart in the exciting tumult of battle, none, we must admit, are so powerful and constant as the soul's thirst for honor and renown… No doubt it is just in war that the abuse of these proud aspirations of the soul must bring upon the human race the most shocking outrages; but by their origin, they are certainly to be counted amongst the noblest feelings which belong to human nature, and in war they are the vivifying principle which gives the enormous body a spirit.

... It is through these aspirations we have been speaking of in commanders, from the highest to the lowest, this sort of energy, this spirit of emulation, these incentives, that the action of armies is chiefly animated and made successful. And now as to that which specially concerns the head of all, we ask, Has there ever been a great commander destitute of the love of honor, or is such a character even conceivable? …

If we now turn to strength of mind or soul, then the first question is, What are we to understand thereby?

Plainly, it is not vehement expressions of feeling, nor easily excited passions, for that would be contrary to all the usage of language; but the power of listening to reason in the midst of the most intense excitement, in the storm of the most violent passions. Should this power depend on strength of understanding alone? We doubt it. The fact that there are men of the greatest intellect who cannot command themselves, certainly proves nothing to the contrary; for we might say that it perhaps requires an understanding of a powerful rather than of a comprehensive nature: but we believe we shall be nearer the truth if we assume that the power of submitting oneself to the control of the understanding, even in moments of the most violent excitement of the feelings, that power which we call self-command, has its root in the heart itself. It is, in point of fact, another feeling, which, in strong minds balances the excited passions without destroying them; and it is only through this equilibrium that the mastery of the understanding is secured. This counterpoise is nothing but a sense of the dignity of man, that noblest pride, that deeply seated desire of the soul, always to act as a being endued with understanding and reason. We may, therefore, say that a strong mind is one which does not lose its balance even under the most violent excitement.…

Now in war, owing to the many and powerful impressions to which the mind is exposed, and, in the uncertainty of all knowledge and of all science, more things occur to distract a man from the road he has entered upon, to make him doubt himself and others, than in any other human activity.

When the discernment is clear and deep, none but general principles and views of action from a high standpoint can be the result; and on these principles the opinion in each particular case immediately under consideration lies, as it were, at anchor...

Certainly one is accustomed to regard the plain honest soldier, as the very opposite of the man of reflection, full of inventions and ideas, or of the brilliant spirit shining in the ornaments of refined education of every kind.

…[However], for each station, from the lowest upwards, to render distinguished services in war, there must be a particular genius. But the title of genius, history and the judgment of posterity only confer, in general, on those minds which have shone in the highest rank, that of commanders-in-chief. The reason is that here, in point of fact, the demand on the reasoning and intellectual powers, generally, is much greater.

To conduct a whole war or its great [...] campaigns, to a successful termination, there must be an intimate knowledge of state [political] policy in its higher relations. The conduct of the war and the [political] policy of the State here coincide; and the general becomes, at the same time, the statesman.

... We say, the general becomes a statesman, but he must not cease to be the general. He takes into view all the relations of the State on the one hand; on the other he must know exactly what he can do with the means at his disposal.

As the diversity and undefined limits of all the circumstances bring a great number of things into consideration in war, as the most of these things can only be estimated according to probability, therefore if the chief of an army does not bring to bear upon all this a mind with an intuitive perception of the truth, a confusion of ideas and views must take place, in the midst of which the judgment will become bewildered. In this sense Napoleon Buonaparte was right when he said that many of the questions which come before a general for decision would make problems for a mathematical calculation, not unworthy of the powers of Newton or Euler.

What is here required from the higher powers of the mind is a sense of unity, and a judgment raised to such a compass as to give the mind an extraordinary faculty of vision, which, in its range, allays and sets aside a thousand dim notions which an ordinary understanding could only bring to light with great effort, and over which it would exhaust itself. But this higher activity of the mind, this glance of genius would still not become matter of history if the qualities of temperament and character of which we have treated did not give it their support.

Truth alone is but a weak motive of action with men, and hence there is always a great difference between knowing and willing, between science and art. The man receives the strongest impulse to action through the feelings, and the most powerful succor, if we may use the expression, through those mixtures of heart and mind, which we have made acquaintance with, as resolution, firmness, perseverance, and force of character.

If, however, this elevated condition of heart and mind in the General did not manifest itself in the general effects resulting from it, and could only be accepted on trust and faith, then it would rarely become matter of history.

All that becomes known of the course of events in war is usually very simple, has a great sameness in appearance; no one on the mere relation of such events perceives the difficulties connected with them which had to be overcome. It is only now and again in the memoirs of Generals, or of those in their confidence, or by reason of some special historical inquiry directed to a particular circumstance that a portion of the many threads composing the whole web is brought to light. The reflections, mental doubts and conflicts which precede the execution of great acts are purposely concealed because they affect political interests, or the recollection of them is accidentally lost because they have been looked upon as mere scaffolding which had to be removed on the completion of the building.

If, now, in conclusion, without venturing upon a closer definition of the higher powers of the soul, we should admit a distinction in the intelligent faculties themselves according to the common ideas established by language, and ask ourselves what kind of mind comes closest to military genius? then a look at the subject as well as at experience will tell us that searching rather than inventive minds, comprehensive minds rather than such as have a special bent, cool rather than fiery heads are those to which in time of war we should prefer to trust the welfare of our brothers and children, the honor and the safety of our fatherland.

Clausewitz QuestionsGuide to unit 5back to unit 5