On War

by Carl von Clausewitz

What are we now to understand by destruction of the enemy’s Army? A diminution of it relatively greater than that on our own side. If we have a great superiority in numbers over the enemy, then naturally the same absolute amount of loss on both sides is for us a smaller one than for him, and consequently may be regarded in itself as an advantage. As we are here considering the combat as divested of all (other) objects, we must also exclude from our consideration the case in which the combat is used only indirectly for a greater destruction of the enemy’s force; consequently also, only that direct gain which has been made in the mutual process of destruction, is to be regarded as the object, for this is an absolute gain, which runs through the whole campaign, and at the end of it will always appear as pure profit. But every other kind of victory over our opponent will either have its motive in other objects, which we have completely excluded here, or it will only yield a temporary relative advantage. An example will make this plain.

If by a skilful disposition we have reduced our opponent to such a dilemma, that he cannot continue the combat without danger, and after some resistance he retires, then we may say, that we have conquered him at that point; but if in this victory we have expended just as many forces as the enemy, then in closing the account of the campaign, there is no gain remaining from this victory, if such a result can be called a victory. Therefore the overcoming the enemy, that is, placing him in such a position that he must give up the fight, counts for nothing in itself, and for that reason cannot come under the definition of object. There remains, therefore, as we have said, nothing over except the direct gain which we have made in the process of destruction; but to this belong not only the losses which have taken place in the course of the combat, but also those which, after the withdrawal of the conquered part, take place as direct consequences of the same.

Now it is known by experience, that the losses in physical forces in the course of a battle seldom present a great difference between victor and vanquished respectively, often none at all, sometimes even one bearing an inverse relation to the result, and that the most decisive losses on the side of the vanquished only commence with the retreat, that is, those which the conqueror does not share with him. The weak remains of battalions already in disorder are cut down by cavalry, exhausted men strew the ground, disabled guns and broken caissons are abandoned, others in the bad state of the roads cannot be removed quickly enough, and are captured by the enemy’s troops, during the night numbers lose their way, and fall defenceless into the enemy’s hands, and thus the victory mostly gains bodily substance after it is already decided. Here would be a paradox, if it did not solve itself in the following manner.

The loss in physical force is not the only one which the two sides suffer in the course of the combat; the moral forces also are shaken, broken, and go to ruin. It is not only the loss in men, horses and guns, but in order, courage, confidence, cohesion and plan, which come into consideration when it is a question whether the fight can be still continued or not. It is principally the moral forces which decide here, and in all cases in which the conqueror has lost as heavily as the conquered, it is these alone.

The comparative relation of the physical losses is difficult to estimate in a battle, but not so the relation of the moral ones. Two things principally make it known. The one is the loss of the ground on which the fight has taken place, the other the superiority of the enemy’s. The more our reserves have diminished as compared with those of the enemy, the more force we have used to maintain the equilibrium; in this at once, an evident proof of the moral superiority of the enemy is given which seldom fails to stir up in the soul of the Commander a certain bitterness of feeling, and a sort of contempt for his own troops. But the principal thing is, that men who have been engaged for a long continuance of time are more or less like burnt-out cinders; their ammunition is consumed; they have melted away to a certain extent; physical and moral energies are exhausted, perhaps their courage is broken as well. Such a force, irrespective of the diminution in its number, if viewed as an organic whole, is very different from what it was before the combat; and thus it is that the loss of moral force may be measured by the reserves that have been used as if it were on a foot-rule.

Lost ground and want of fresh reserves, are, therefore, usually the principal causes which determine a retreat; but at the same time we by no means exclude or desire to throw in the shade other reasons, which may lie in the interdependence of parts of the Army, in the general plan, &c.

Every combat is therefore the bloody and destructive measuring of the strength of forces, physical and moral; whoever at the close has the greatest amount of both left is the conqueror.

In the combat the loss of moral force is the chief cause of the decision; after that is given, this loss continues to increase until it reaches its culminating-point at the close of the whole act. This then is the opportunity the victor should seize to reap his harvest by the utmost possible restrictions of his enemy’s forces, the real object of engaging in the combat. On the beaten side, the loss of all order and control often makes the prolongation of resistance by individual units, by the further punishment they are certain to suffer, more injurious than useful to the whole. The spirit of the mass is broken; the original excitement about losing or winning, through which danger was forgotten, is spent, and to the majority danger now appears no longer an appeal to their courage, but rather the endurance of a cruel punishment. Thus the instrument in the first moment of the enemy’s victory is weakened and blunted, and therefore no longer fit to repay danger by danger.

This period, however, passes; the moral forces of the conquered will recover by degrees, order will be restored, courage will revive, and in the majority of cases there remains only a small part of the superiority obtained, often none at all. In some cases, even, although rarely, the spirit of revenge and intensified hostility may bring about an opposite result. On the other hand, whatever is gained in killed, wounded, prisoners, and guns captured can never disappear from the account.

The losses in a battle consist more in killed and wounded; those after the battle, more in artillery taken and prisoners. The first the conqueror shares with the conquered, more or less, but the second not; and for that reason they usually only take place on one side of the conflict, at least, they are considerably in excess on one side.