On War
Clausewitz (1827)
We have here to deal with a conception which in real life diffuses many kinds of illusory light. A clear definition and development of the idea is therefore necessary, and we hope to be allowed a short analysis.
War is the shock of two opposing forces in collision with each other, from which it follows as a matter of course that the stronger not only destroys the other, but carries it forward with it in its movement. This fundamentally admits of no successive action of powers, but makes the simultaneous application of all forces intended for the shock appear as a primordial law of War.
So it is in reality, but only so far as the struggle resembles also in practice a mechanical shock, but when it consists in a lasting, mutual action of destructive forces, then we can certainly imagine a successive action of forces. This is the case in tactics, principally because firearms form the basis of all tactics, but also for other reasons as well. If in a fire combat 1000 men are opposed to 500, then the gross loss is calculated from the amount of the enemy’s force and our own; 1000 men fire twice as many shots as 500, but more shots will take effect on the 1000 than on the 500 because it is assumed that they stand in closer order than the other. If we were to suppose the number of hits to be double, then the losses on each side would be equal. From the 500 there would be for example 200 disabled, and out of the body of 1000 likewise the same; now if the 500 had kept another body of equal number quite out of fire, then both sides would have 800 effective men; but of these, on the one side there would be 500 men quite fresh, fully supplied with ammunition, and in their full vigour; on the other side only 800 all alike shaken in their order, in want of sufficient ammunition and weakened in physical force. The assumption that the 1000 men merely on account of their greater number would lose twice as many as 500 would have lost in their place, is certainly not correct; therefore the greater loss which the side suffers that has placed the half of its force in reserve, must be regarded as a disadvantage in that original formation; further it must be admitted, that in the generality of cases the 1000 men would have the advantage at the first commencement of being able to drive their opponent out of his position and force him to a retrograde movement; now, whether these two advantages are a counterpoise to the disadvantage of finding ourselves with 800 men to a certain extent disorganised by the combat, opposed to an enemy who is not materially weaker in numbers and who has 500 quite fresh troops, is one that cannot be decided by pursuing an analysis further, we must here rely upon experience, and there will scarcely be an officer experienced in War who will not in the generality of cases assign the advantage to that side which has the fresh troops.
In this way it becomes evident how the employment of too many forces in combat may be disadvantageous; for whatever advantages the superiority may give in the first moment, we may have to pay dearly for in the next.
But this danger only endures as long as the disorder, the state of confusion and weakness lasts, in a word, up to the crisis which every combat brings with it even for the conqueror. Within the duration of this relaxed state of exhaustion, the appearance of a proportionate number of fresh troops is decisive.
But when this disordering effect of victory stops, and therefore only the moral superiority remains which every victory gives, then it is no longer possible for fresh troops to restore the combat, they would only be carried along in the general movement; a beaten Army cannot be brought back to victory a day after by means of a strong reserve. Here we find ourselves at the source of a highly material difference between tactics and strategy.
The tactical results, the results within the four corners of the battle, and before its close, lie for the most part within the limits of that period of disorder and weakness. But the strategic result, that is to say, the result of the total combat, of the victories realised, let them be small or great, lies completely (beyond) outside of that period. It is only when the results of partial combats have bound themselves together into an independent whole, that the strategic result appears, but then, the state of crisis is over, the forces have resumed their original form, and are now only weakened to the extent of those actually destroyed (placed hors de combat).
The consequence of this difference is, that tactics can make a continued use of forces, Strategy only a simultaneous one.[*]
[*] See chaps. xiii., and xiv., Book iii and chap. xxix. Book V.--tr.
If i cannot, in tactics, decide all by the first success, if i have to fear the next moment, it follows of itself that i employ only so much of my force for the success of the first moment as appears sufficient for that object, and keep the rest beyond the reach of fire or conflict of any kind, in order to be able to oppose fresh troops to fresh, or with such to overcome those that are exhausted. but it is not so in strategy. partly, as we have just shown, it has not so much reason to fear a reaction after a success realised, because with that success the crisis stops; partly all the forces strategically employed are not necessarily weakened. only so much of them as have been tactically in conflict with the enemy’s force, that is, engaged in partial combat, are weakened by it; consequently, only so much as was unavoidably necessary, but by no means all which was strategically in conflict with the enemy, unless tactics has expended them unnecessarily. corps which, on account of the general superiority in numbers, have either been little or not at all engaged, whose presence alone has assisted in the result, are after the decision the same as they were before, and for new enterprises as efficient as if they had been entirely inactive. how greatly such corps which thus constitute our excess may contribute to the total success is evident in itself; indeed, it is not difficult to see how they may even diminish considerably the loss of the forces engaged in tactical, conflict on our side.
If, therefore, in Strategy the loss does not increase with the number of the troops employed, but is often diminished by it, and if, as a natural consequence, the decision in our favor is, by that means, the more certain, then it follows naturally that in Strategy we can never employ too many forces, and consequently also that they must be applied simultaneously to the immediate purpose.
But we must vindicate this proposition upon another ground. We have hitherto only spoken of the combat itself; it is the real activity in War, but men, time, and space, which appear as the elements of this activity, must, at the same time, be kept in view, and the results of their influence brought into consideration also.
Fatigue, exertion, and privation constitute in War a special principle of destruction, not essentially belonging to contest, but more or less inseparably bound up with it, and certainly one which especially belongs to Strategy. They no doubt exist in tactics as well, and perhaps there in the highest degree; but as the duration of the tactical acts is shorter, therefore the small effects of exertion and privation on them can come but little into consideration. But in Strategy on the other hand, where time and space, are on a larger scale, their influence is not only always very considerable, but often quite decisive. It is not at all uncommon for a victorious Army to lose many more by sickness than on the field of battle.
If, therefore, we look at this sphere of destruction in Strategy in the same manner as we have considered that of fire and close combat in tactics, then we may well imagine that everything which comes within its vortex will, at the end of the campaign or of any other strategic period, be reduced to a state of weakness, which makes the arrival of a fresh force decisive. We might therefore conclude that there is a motive in the one case as well as the other to strive for the first success with as few forces as possible, in order to keep up this fresh force for the last.
In order to estimate exactly this conclusion, which, in many cases in practice, will have a great appearancetruth, we must direct our attention to the separate ideas which it contains. In the first place, we must not confuse the notion of reinforcement with that of fresh unused troops. There are few campaigns at the end of which an increase of force is not earnestly desired by the conqueror as well as the conquered, and indeed should appear decisive; but that is not the point here, for that increase of force could not be necessary if the force had been so much larger at the first. But it would be contrary to all experience to suppose that an Army coming fresh into the field is to be esteemed higher in point of moral value than an Army already in the field, just as a tactical reserve is more to be esteemed than a body of troops which has been already severely handled in the fight. Just as much as an unfortunate campaign lowers the courage and moral powers of an Army, a successful one raises these elements in their value. In the generality of cases, therefore, these influences are compensated, and then there remains over and above as clear gain the habituation to War. We should besides look more here to successful than to unsuccessful campaigns, because when the greater probability of the latter may be seen beforehand, without doubt forces are wanted, and, therefore, the reserving a portion for future use is out of the question.
This point being settled, then the question is, Do the losses which a force sustains through fatigues and privations increase in proportion to the size of the force, as is the case in a combat? And to that we answer “No.”
The fatigues of War result in a great measure from the dangers with which every moment of the act of War is more or less impregnated. To encounter these dangers at all points, to proceed onwards with security in the execution of one’s plans, gives employment to a multitude of agencies which make up the tactical and strategic service of the Army. This service is more difficult the weaker an Army is, and easier as its numerical superiority over that of the enemy increases. Who can doubt this? A campaign against a much weaker enemy will therefore cost smaller efforts than against one just as strong or stronger.
So much for the fatigues. It is somewhat different with the privations; they consist chiefly of two things, the want of food, and the want of shelter for the troops, either in quarters or in suitable camps. Both these wants will no doubt be greater in proportion as the number of men on one spot is greater. But does not the superiority in force afford also the best means of spreading out and finding more room, and therefore more means of subsistence and shelter?
If Buonaparte, in his invasion of Russia in 1812, concentrated his Army in great masses upon one single road in a manner never heard of before, and thus caused privations equally unparalleled, we must ascribe it to his maxim that it is impossible to be too strong at the decisive point. Whether in this instance he did not strain the principle too far is a question which would be out of place here; but it is certain that, if he had made a point of avoiding the distress which was by that means brought about, he had only to advance on a greater breadth of front. Room was not wanted for the purpose in Russia, and in very few cases can it be wanted. Therefore, from this no ground can be deduced to prove that the simultaneous employment of very superior forces must produce greater weakening. But now, supposing that in spite of the general relief afforded by setting apart a portion of the Army, wind and weather and the toils of War had produced a diminution even on the part which as a spare force had been reserved for later use, still we must take a comprehensive general view of the whole, and therefore ask, Will this diminution of force suffice to counterbalance the gain in forces, which we, through our superiority in numbers, may be able to make in more ways than one?
But there still remains a most important point to be noticed. In a partial combat, the force required to obtain a great result can be approximately estimated without much difficulty, and, consequently, we can form an idea of what is superfluous. In Strategy this may be said to be impossible, because the strategic result has no such well-defined object and no such circumscribed limits as the tactical. Thus what can be looked upon in tactics as an excess of power, must be regarded in Strategy as a means to give expansion to success, if opportunity offers for it; with the magnitude of the success the gain in force increases at the same time, and in this way the superiority of numbers may soon reach a point which the most careful economy of forces could never have attained.
By means of his enormous numerical superiority, Buonaparte was enabled to reach Moscow in 1812, and to take that central capital. Had he by means of this superiority succeeded in completely defeating the Russian Army, he would, in all probability, have concluded a peace in Moscow which in any other way was much less attainable. This example is used to explain the idea, not to prove it, which would require a circumstantial demonstration, for which this is not the place.[*]
[*] Compare Book vii., second edition, p. 56.
All these reflections bear merely upon the idea of a successive employment of forces, and not upon the conception of a reserve properly so called, which they, no doubt, come in contact with throughout, but which, as we shall see in the following chapter, is connected with some other considerations.
What we desire to establish here is, that if in tactics the military force through the mere duration of actual employment suffers a diminution of power, if time, therefore, appears as a factor in the result, this is not the case in Strategy in a material degree. The destructive effects which are also produced upon the forces in Strategy by time, are partly diminished through their mass, partly made good in other ways, and, therefore, in Strategy it cannot be an object to make time an ally on its own account by bringing troops successively into action.
We say on “its own account,” for the influence which time, on account of other circumstances which it brings about but which are different from itself can have, indeed must necessarily have, for one of the two parties, is quite another thing, is anything but indifferent or unimportant, and will be the subject of consideration hereafter.
The rule which we have been seeking to set forth is, therefore, that all forces which are available and destined for a strategic object should be simultaneously applied to it; and this application will be so much the more complete the more everything is compressed into one act and into one movement.
But still there is in Strategy a renewal of effort and a persistent action which, as a chief means towards the ultimate success, is more particularly not to be overlooked, it is the continual development of new forces. This is also the subject of another chapter, and we only refer to it here in order to prevent the reader from having something in view of which we have not been speaking.
We now turn to a subject very closely connected with our present considerations, which must be settled before full light can be thrown on the whole, we mean the strategic reserve.