On War

by Carl von Clausewitz

We think, now, that in this way we have gone over and brought into view everything comprised in the province of the defensive. At the same time, there are subjects of sufficient importance in themselves to form separate chapters, that is, points for consideration in themselves, and these we must also study; for example, the nature and influence of fortified places, entrenched camps, defence of mountains and rivers, operations against the flank, etc., etc. We shall treat of them in subsequent chapters, but none of these things lie outside of the preceding sequence of ideas; they are only to be regarded as a closer application of it to locality and circumstances. That order of ideas has been deduced from the conception of the defensive, and from its relation to the offensive; we have connected these simple ideas with reality, and therefore shown the way by which we may return again from the reality to those simple ideas, and obtain firm ground, and not be forced in reasoning to take refuge on points of support which themselves vanish in the air.

But resistance by the sword may wear such an altered appearance, assume such a different character, through the multiplicity of ways of combining battles, especially in cases where these are not actually realised, but become effectual merely through their possibility, that we might incline to the opinion that there must be some other efficient active principle still to be discovered; between the sanguinary defeat in a simple battle, and the effects of strategic combinations which do not bring the thing nearly so far as actual combat, there seems such a difference, that it is necessary to suppose some fresh force, something in the same way as astronomers have decided on the existence of other planets from the great space between Mars and Jupiter.

If the assailant finds the defender in a strong position which he thinks he cannot take, or behind a large river which he thinks he cannot cross, or even if he fears that by advancing further he will not be able to subsist his army, in all these cases it is nothing but the sword of the defensive which produces the effect; for it is the fear of being conquered by this sword, either in a great battle or at some specially important points, which compels the aggressor to stop, only he will either not admit that at all, or does not admit it in a straightforward way.

Now even if it is granted that, where there has been a decision without bloodshed, the combat merely offered, but not accepted, has been the ultimate cause of the decision, it will still be thought that in such cases the really effectual principle is the strategic combination of these combats and not their tactical decision, and that this superiority of the strategic combination could only have been thought of because there are other defensive means which may be considered besides an actual appeal to the sword. We admit this, and it brings us just to the point we wished to arrive at, which is as follows: if the tactical result of a battle must be the foundation of all strategic combinations, then it is always possible and to be feared that the assailant may lay hold of this principle, and above all things direct his efforts to be superior in the hour of decision, in order to baffle the strategic combination; and that therefore this strategic combination can never be regarded as something all-sufficient in itself; that it only has a value when either on one ground or another we can look forward to the tactical solution without any misgivings. In order to make ourselves intelligible in a few words, we shall merely call to our readers’ recollection how such a general as Buonaparte marched without hesitation through the whole web of his opponents’ strategic plans, to seek for the battle itself, because he had no doubts as to its issue. Where, therefore, strategy had not directed its whole effort to ensure a preponderance over him in this battle, where it engaged in finer (feebler) plans, there it was rent asunder like a cobweb. But a general like Daun might be checked by such measures; it would therefore be folly to offer Buonaparte and his army what the Prussian army of the Seven Years’ War dared to offer Daun and his contemporaries. Why?—Because Buonaparte knew right well that all depended on the tactical issue, and made certain of gaining it; whereas with Daun it was very different in both respects.

On this account we hold it therefore to be serviceable to show that every strategic combination rests only upon the tactical results, and that these are everywhere, in the bloody as well as in the bloodless solution, the real fundamental grounds of the ultimate decision. It is only if we have no reason to fear that decision, whether on account of the character or the situation of the enemy, or on account of the moral and physical equality of the two armies, or on account of our own superiority—it is only then that we can expect something from strategic combinations in themselves without battles.

Now if a great many campaigns are to be found within the compass of military history in which the assailant gives up the offensive without any blood being spilt in fight, in which, therefore, strategic combinations show themselves effectual to that degree, this may lead to the idea that these combinations have at least great inherent force in themselves, and might in general decide the affair alone, where too great a preponderance in the tactical results is not supposed on the side of the aggressor. To this we answer that, if the question is about things which have their origin in the theatre of war, and consequently belong to the war itself, this idea is also equally false; and we add that the cause of the failure of most attacks is to be found in the higher, the political relations of war.

The general relations out of which a war springs, and which naturally constitute its foundation, determine also its character; on this subject we shall have more to say hereafter, in treating of the plan of a war. But these general relations have converted most wars into half-and-half things, into which real hostility has to force its way through such a conflict of interests, that it is only a very weak element at the last. This effect must naturally show itself chiefly and with most force on the side of the offensive, the side of positive action. One cannot therefore wonder if such a short-winded, consumptive attack is brought to a standstill by the touch of a finger. Against a weak resolution so fettered by a thousand considerations, that it has hardly any existence, a mere show of resistance is often enough.

It is not the number of unassailable positions in all directions, not the formidable look of the dark mountain masses encamped round the theatre of war, or the broad river which passes through it, not the ease with which certain combinations of battles can effectually paralyse the muscle which should strike the blow against us—none of these things are the true causes of the numerous successes which the defensive gains on bloodless fields; the cause lies in the weakness of the will with which the assailant puts forward his hesitating feet.

These counteracting influences may and ought to be taken into consideration, but they should only be looked upon in their true light, and their effects should not be ascribed to other things, namely the things of which alone we are now treating. We must not omit to point out in an emphatic manner how easily military history in this respect may become a perpetual liar and deceiver if criticism is not careful about taking a correct point of view.

Let us now consider, in what we may call their ordinary form, the many offensive campaigns which have miscarried without a bloody solution.