On War

by Carl von Clausewitz

The assailant advances into the enemy’s country, drives back his opponent a little way, but finds it too serious a matter to bring on a decisive battle. He therefore remains standing opposite to him; acts as if he had made a conquest, and had nothing else to do but to protect it; as if it was the enemy’s business to seek the battle, as if he offered it to him daily, etc., etc. These are the representations with which the commander deludes his army, his government, the world, even himself. But the truth is, that he finds the enemy in a position too strong for him. We do not now speak of a case where an aggressor does not proceed with his attack because he can make no use of a victory, because at the end of his first bound he has not enough impulsive force left to begin another. Such a case supposes an attack which has been successful, a real conquest; but we have here in view the case where an assailant sticks fast half way to his intended conquest.

He is now waiting to take advantage of favourable circumstances, of which favourable circumstances there is in general no prospect, for the aggression now intended shows at once that there is no better prospect from the future than from the present; it is, therefore, a further illusion. If now, as is commonly the case, the undertaking is in connection with other simultaneous operations, then what they do not want to do themselves is transferred to other shoulders, and their own inactivity is ascribed to want of support and proper co-operation. Insurmountable obstacles are talked of, and motives in justification are discovered in the most confused and subtil considerations. Thus the forces of the assailant are wasted away in inactivity, or rather in a partial activity, destitute of any utility. The defensive gains time, the greatest gain to him; bad weather arrives, and the aggression ends by the return of the aggressor to winter quarters in his own theatre of war.

A tissue of false representations thus passes into history in place of the simple real ground of absence of any result, namely fear of the enemy’s sword. When criticism takes up such a campaign, it wearies itself in the discussion of a number of motives and counter-motives, which give no satisfactory result, because they all dwindle into vapour, and we have not descended to the real foundation of the truth. The opposition through which the elementary energy of war, and therefore of the offensive in particular, becomes weakened, lies for the most part in the relations and views of states, and these are always concealed from the world, from the mass of the people belonging to the state, as well as from the army, and very often from the general-in-chief. No one will account for his faint-heartedness by the admission that he feared he could not attain the desired object with the force at his disposal, or that new enemies would be roused, or that he did not wish to make his allies too powerful, etc. Such things are hushed up; but as occurrences have to be placed before the world in a presentable form, therefore the commander is obliged, either on his own account or on that of his government to pass off a tissue of fictitious motives. This ever-recurring deception in military dialectics has ossified into systems in theory, which, of course, are equally devoid of truth. Theory can never be deduced from the essence of things except by following the simple thread of cause and effect, as we have tried to do.

If we look at military history with this feeling of suspicion, then a great parade of mere words about offensive and defensive collapses, and the simple idea of it, which we have given, comes forward of itself. We believe it therefore to be applicable to the whole domain of the defensive, and that we must adhere closely to it in order to obtain that clear view of the mass of events by which alone we can form correct judgments.

We have still to inquire into the question of the employment of these different forms of defence.

As they are merely gradations of the same which must be purchased by a higher sacrifice, corresponding to the increased intensity of the form, there would seem to be sufficient in that view to indicate always to the general which he should choose, provided there are no other circumstances which interfere. He would, in fact, choose that form which appeared sufficient to give his force the requisite degree of defensive power and no more, that there might be no unnecessary waste of his force. But we must not overlook the circumstance that the room given for choice amongst these different forms is generally very circumscribed, because other circumstances which must be attended to necessarily urge a preference for one or other of them. For a retreat into the interior of the country a considerable superficial space is required, or such a condition of things as existed in Portugal (1810), where one ally (England) gave support in rear, and another (Spain) with its wide territory, considerably diminished the impulsive force of the enemy. The position of the fortresses more on the frontier or more in the interior may likewise decide for or against such a plan; but still more the nature of the country and ground, the character, habits, and feelings of the inhabitants. The choice between an offensive or defensive battle may be decided by the plans of the enemy, by the peculiar qualities of both armies and their generals; lastly, the possession of an excellent position or line of defence, or the want of them may determine for one or the other;—in short, at the bare mention of these things, we can perceive that the choice of the form of defensive must in many cases be determined more by them than by the mere relative strength of the armies. As we shall hereafter enter more into detail on the more important subjects which have just been touched upon, the influence which they must have upon the choice will then develop itself more distinctly, and in the end the whole will be methodised in the Book on Plans of Wars and Campaigns.

But this influence will not, in general, be decisive unless the inequality in the strength of the opposing armies is trifling; in the opposite case (as in the generality of cases), the relation of the numerical strength will be decisive. There is ample proof, in military history, that it has done so heretofore, and that without the chain of reasoning by which it has been brought out here; therefore in a manner intuitively by mere tact of judgment, like most things that happen in war. It was the same general who at the head of the same army, and on the same theatre of war, fought the battle of Hohenfriedberg, and at another time took up the camp of Bunzelwitz. Therefore even Frederick the Great, a general above all inclined to the offensive as regards the battle, saw himself compelled at last, by a great disproportion of force, to resort to a real defensive position; and Buonaparte, who was once in the habit of falling on his enemy like a wild boar, have we not seen him, when the proportion of force turned against him, in August and September, 1813, turn himself hither and thither as if he had been pent up in a cage, instead of rushing forward recklessly upon some one of his adversaries? And in October of the same year, when the disproportion reached its climax, have we not seen him at Leipsic, seeking shelter in the angle formed by the Parth, the Elster, and Pleiss, as it were waiting for his enemy in the corner of a room, with his back against the wall?

We cannot omit to observe, that from this chapter, more than from any other in our book, it is plainly shown that our object is not to lay down new principles and methods of conducting war, but merely to investigate what has long existed in its innermost relations, and to reduce it to its simplest elements.

CHAPTER IX.
Defensive Battle

We have said, in the preceding chapter, that the defender, in his defensive, would make use of a battle, technically speaking, of a purely offensive character, if, at the moment the enemy invades his theatre of war, he marches against him and attacks him; but that he might also wait for the appearance of the enemy in his front, and then pass over to the attack; in which case also the battle tactically would be again an offensive battle, although in a modified form; and lastly, that he might wait till the enemy attacked his position, and then oppose him both by holding a particular spot, and by offensive action with portions of his force. In all this we may imagine several different gradations and shades, deviating always more from the principle of a positive counterstroke, and passing into that of the defence of a spot of ground. We cannot here enter on the subject of how far this should be carried, and which is the most advantageous proportion of the two elements of offensive and defensive, as regards the winning a decisive victory. But we maintain that when such a result is desired, the offensive part of the battle should never be completely omitted, and we are convinced that all the effects of a decisive victory may and must be produced by this offensive part, just as well as in a purely tactical offensive battle.