On War

by Carl von Clausewitz

To make a sound theory it is most essential to separate these two activities, for it is easy to see that if every act of War is to begin with the preparation of military forces, and to presuppose forces so organised as a primary condition for conducting War, that theory will only be applicable in the few cases to which the force available happens to be exactly suited. If, on the other hand, we wish to have a theory which shall suit most cases, and will not be wholly useless in any case, it must be founded on those means which are in most general use, and in respect to these only on the actual results springing from them.

The conduct of War is, therefore, the formation and conduct of the fighting. If this fighting was a single act, there would be no necessity for any further subdivision, but the fight is composed of a greater or less number of single acts, complete in themselves, which we call combats, as we have shown in the first chapter of the first book, and which form new units. From this arises the totally different activities, that of the formation and conduct of these single combats in themselves, and the combination of them with one another, with a view to the ultimate object of the War. The first is called tactics, the other strategy.

This division into tactics and strategy is now in almost general use, and every one knows tolerably well under which head to place any single fact, without knowing very distinctly the grounds on which the classification is founded. But when such divisions are blindly adhered to in practice, they must have some deep root. We have searched for this root, and we might say that it is just the usage of the majority which has brought us to it. On the other hand, we look upon the arbitrary, unnatural definitions of these conceptions sought to be established by some writers as not in accordance with the general usage of the terms.

According to our classification, therefore, tactics is the theory of the use of military forces in combat. Strategy is the theory of the use of combats for the object of the War.

The way in which the conception of a single, or independent combat, is more closely determined, the conditions to which this unit is attached, we shall only be able to explain clearly when we consider the combat; we must content ourselves for the present with saying that in relation to space, therefore in combats taking place at the same time, the unit reaches just as far as personal command reaches; but in regard to time, and therefore in relation to combats which follow each other in close succession, it reaches to the moment when the crisis which takes place in every combat is entirely passed.

That doubtful cases may occur, cases, for instance, in which several combats may perhaps be regarded also as a single one, will not overthrow the ground of distinction we have adopted, for the same is the case with all grounds of distinction of real things which are differentiated by a gradually diminishing scale. There may, therefore, certainly be acts of activity in War which, without any alteration in the point of view, may just as well be counted strategic as tactical; for example, very extended positions resembling a chain of posts, the preparations for the passage of a river at several points, &c.

Our classification reaches and covers only the use of the military force. But now there are in War a number of activities which are subservient to it, and still are quite different from it; sometimes closely allied, sometimes less near in their affinity. All these activities relate to the maintenance of the military force. In the same way as its creation and training precede its use, so its maintenance is always a necessary condition. But, strictly viewed, all activities thus connected with it are always to be regarded only as preparations for fighting; they are certainly nothing more than activities which are very close to the action, so that they run through the hostile act alternate in importance with the use of the forces. We have therefore a right to exclude them as well as the other preparatory activities from the Art of War in its restricted sense, from the conduct of War properly so called; and we are obliged to do so if we would comply with the first principle of all theory, the elimination of all heterogeneous elements. Who would include in the real “conduct of War” the whole litany of subsistence and administration, because it is admitted to stand in constant reciprocal action with the use of the troops, but is something essentially different from it?

We have said, in the third chapter of our first book, that as the fight or combat is the only directly effective activity, therefore the threads of all others, as they end in it, are included in it. By this we meant to say that to all others an object was thereby appointed which, in accordance with the laws peculiar to themselves, they must seek to attain. Here we must go a little closer into this subject.

The subjects which constitute the activities outside of the combat are of various kinds.

The one part belongs, in one respect, to the combat itself, is identical with it, whilst it serves in another respect for the maintenance of the military force. The other part belongs purely to the subsistence, and has only, in consequence of the reciprocal action, a limited influence on the combats by its results. The subjects which in one respect belong to the fighting itself are marches, camps, and cantonments, for they suppose so many different situations of troops, and where troops are supposed there the idea of the combat must always be present.