On War
Clausewitz (1827)

Chapter XII. Strategic Means of Utilising Victory

The more difficult part, viz., that of perfectly preparing the victory, is a silent service of which the merit belongs to Strategy and yet for which it is hardly sufficiently commended. It appears brilliant and full of renown by turning to good account a victory gained.

What may be the special object of a battle, how it is connected with the whole system of a War, whither the career of victory may lead according to the nature of circumstances, where its culminating-point lies--all these are things which we shall not enter upon until hereafter. But under any conceivable circumstances the fact holds good, that without a pursuit no victory can have a great effect, and that, however short the career of victory may be, it must always lead beyond the first steps in pursuit; and in order to avoid the frequent repetition of this, we shall now dwell for a moment on this necessary supplement of victory in general.

The pursuit of a beaten Army commences at the moment that Army, giving up the combat, leaves its position; all previous movements in one direction and another belong not to that but to the progress of the battle itself. Usually victory at the moment here described, even if it is certain, is still as yet small and weak in its proportions, and would not rank as an event of any great positive advantage if not completed by a pursuit on the first day. Then it is mostly, as we have before said, that the trophies which give substance to the victory begin to be gathered up. Of this pursuit we shall speak in the next place.

Usually both sides come into action with their physical powers considerably deteriorated, for the movements immediately preceding have generally the character of very urgent circumstances. The efforts which the forging out of a great combat costs, complete the exhaustion; from this it follows that the victorious party is very little less disorganised and out of his original formation than the vanquished, and therefore requires time to reform, to collect stragglers, and issue fresh ammunition to those who are without. All these things place the conqueror himself in the state of crisis of which we have already spoken. If now the defeated force is only a detached portion of the enemy’s Army, or if it has otherwise to expect a considerable reinforcement, then the conqueror may easily run into the obvious danger of having to pay dear for his victory, and this consideration, in such a case, very soon puts an end to pursuit, or at least restricts it materially. Even when a strong accession of force by the enemy is not to be feared, the conqueror finds in the above circumstances a powerful check to the vivacity of his pursuit. There is no reason to fear that the victory will be snatched away, but adverse combats are still possible, and may diminish the advantages which up to the present have been gained. Moreover, at this moment the whole weight of all that is sensuous in an Army, its wants and weaknesses, are dependent on the will of the Commander. All the thousands under his command require rest and refreshment, and long to see a stop put to toil and danger for the present; only a few, forming an exception, can see and feel beyond the present moment, it is only amongst this little number that there is sufficient mental vigour to think, after what is absolutely necessary at the moment has been done, upon those results which at such a moment only appear to the rest as mere embellishments of victory--as a luxury of triumph. But all these thousands have a voice in the council of the General, for through the various steps of the military hierarchy these interests of the sensuous creature have their sure conductor into the heart of the Commander. He himself, through mental and bodily fatigue, is more or less weakened in his natural activity, and thus it happens then that, mostly from these causes, purely incidental to human nature, less is done than might have been done, and that generally what is done is to be ascribed entirely to the thirst for glory, the energy, indeed also the hard- heartedness of the General-in-Chief. It is only thus we can explain the hesitating manner in which many Generals follow up a victory which superior numbers have given them. The first pursuit of the enemy we limit in general to the extent of the first day, including the night following the victory. At the end of that period the necessity of rest ourselves prescribes a halt in any case.

This first pursuit has different natural degrees.

The first is, if cavalry alone are employed; in that case it amounts usually more to alarming and watching than to pressing the enemy in reality, because the smallest obstacle of ground is generally sufficient to check the pursuit. Useful as cavalry may be against single bodies of broken demoralised troops, still when opposed to the bulk of the beaten Army it becomes again only the auxiliary arm, because the troops in retreat can employ fresh reserves to cover the movement, and, therefore, at the next trifling obstacle of ground, by combining all arms they can make a stand with success. The only exception to this is in the case of an army in actual flight in a complete state of dissolution.

The second degree is, if the pursuit is made by a strong advance-guard composed of all arms, the greater part consisting naturally of cavalry. Such a pursuit generally drives the enemy as far as the nearest strong position for his rear-guard, or the next position affording space for his Army. Neither can usually be found at once, and, therefore, the pursuit can be carried further; generally, however, it does not extend beyond the distance of one or at most a couple of leagues, because otherwise the advance- guard would not feel itself sufficiently supported. The third and most vigorous degree is when the victorious Army itself continues to advance as far as its physical powers can endure. In this case the beaten Army will generally quit such ordinary positions as a country usually offers on the mere show of an attack, or of an intention to turn its flank; and the rear-guard will be still less likely to engage in an obstinate resistance.

In all three cases the night, if it sets in before the conclusion of the whole act, usually puts an end to it, and the few instances in which this has not taken place, and the pursuit has been continued throughout the night, must be regarded as pursuits in an exceptionally vigorous form.

If we reflect that in fighting by night everything must be, more or less, abandoned to chance, and that at the conclusion of a battle the regular cohesion and order of things in an army must inevitably be disturbed, we may easily conceive the reluctance of both Generals to carrying on their business under such disadvantageous conditions. If a complete dissolution of the vanquished Army, or a rare superiority of the victorious Army in military virtue does not ensure success, everything would in a manner be given up to fate, which can never be for the interest of any one, even of the most fool-hardy General. As a rule, therefore, night puts an end to pursuit, even when the battle has only been decided shortly before darkness sets in. This allows the conquered either time for rest and to rally immediately, or, if he retreats during the night it gives him a march in advance. After this break the conquered is decidedly in a better condition; much of that which had been thrown into confusion has been brought again into order, ammunition has been renewed, the whole has been put into a fresh formation. Whatever further encounter now takes place with the enemy is a new battle not a continuation of the old, and although it may be far from promising absolute success, still it is a fresh combat, and not merely a gathering up of the debris by the victor.

When, therefore, the conqueror can continue the pursuit itself throughout the night, if only with a strong advance- guard composed of all arms of the service, the effect of the victory is immensely increased, of this the battles of Leuthen and La Belle Alliance[*] are examples.

[*] Waterloo.

The whole action of this pursuit is mainly tactical, and we only dwell upon it here in order to make plain the difference which through it may be produced in the effect of a victory.

This first pursuit, as far as the nearest stopping-point, belongs as a right to every conqueror, and is hardly in any way connected with his further plans and combinations. These may considerably diminish the positive results of a victory gained with the main body of the Army, but they cannot make this first use of it impossible; at least cases of that kind, if conceivable at all, must be so uncommon that they should have no appreciable influence on theory. And here certainly we must say that the example afforded by modern Wars opens up quite a new field for energy. In preceding Wars, resting on a narrower basis, and altogether more circumscribed in their scope, there were many unnecessary conventional restrictions in various ways, but particularly in this point. The conception, honour of victory seemed to Generals so much by far the chief thing that they thought the less of the complete destruction of the enemy’s military force, as in point of fact that destruction of force appeared to them only as one of the many means in War, not by any means as the principal, much less as the only means; so that they the more readily put the sword in its sheath the moment the enemy had lowered his. Nothing seemed more natural to them than to stop the combat as soon as the decision was obtained, and to regard all further carnage as unnecessary cruelty. Even if this false philosophy did not determine their resolutions entirely, still it was a point of view by which representations of the exhaustion of all powers, and physical impossibility of continuing the struggle, obtained readier evidence and greater weight. Certainly the sparing one’s own instrument of victory is a vital question if we only possess this one, and foresee that soon the time may arrive when it will not be sufficient for all that remains to be done, for every continuation of the offensive must lead ultimately to complete exhaustion. But this calculation was still so far false, as the further loss of forces by a continuance of the pursuit could bear no proportion to that which the enemy must suffer. That view, therefore, again could only exist because the military forces were not considered the vital factor. And so we find that in former Wars real heroes only--such as Charles xii., Marlborough, Eugene, Frederick the Great--added a vigorous pursuit to their victories when they were decisive enough, and that other Generals usually contented themselves with the possession of the field of battle. In modern times the greater energy infused into the conduct of Wars through the greater importance of the circumstances from which they have proceeded has thrown down these conventional barriers; the pursuit has become an all-important business for the conqueror; trophies have on that account multiplied in extent, and if there are cases also in modern Warfare in which this has not been the case, still they belong to the list of exceptions, and are to be accounted for by peculiar circumstances.

At Gorschen[*] and Bautzen nothing but the superiority of the allied cavalry prevented a complete rout, at Gross Beeren and Dennewitz the ill-will of Bernadotte, the Crown Prince of Sweden; at Laon the enfeebled personal condition of Bluecher, who was then seventy years old and at the moment confined to a dark room owing to an injury to his eyes.

[*] Gorschen or Lutzen, May 2, 1813; Gross Beeren and Dennewitz, August 22, 1813; Bautzen. May 22, 1913; Laon, March 10 1813.

But Borodino is also an illustration to the point here, and we cannot resist saying a few more words about it, partly because we do not consider the circumstances are explained simply by attaching blame to Buonaparte, partly because it might appear as if this, and with it a great number of similar cases, belonged to that class which we have designated as so extremely rare, cases in which the general relations seize and fetter the General at the very beginning of the battle. French authors in particular, and great admirers of Buonaparte (Vaudancourt, Chambray, Se'gur), have blamed him decidedly because he did not drive the Russian Army completely off the field, and use his last reserves to scatter it, because then what was only a lost battle would have been a complete rout. We should be obliged to diverge too far to describe circumstantially the mutual situation of the two Armies; but this much is evident, that when Buonaparte passed the Niemen with his Army the same corps which afterwards fought at Borodino numbered 300,000 men, of whom now only 120,000 remained, he might therefore well be apprehensive that he would not have enough left to march upon Moscow, the point on which everything seemed to depend. The victory which he had just gained gave him nearly a certainty of taking that capital, for that the Russians would be in a condition to fight a second battle within eight days seemed in the highest degree improbable; and in Moscow he hoped to find peace. No doubt the complete dispersion of the Russian Army would have made this peace much more certain; but still the first consideration was to get to Moscow, that is, to get there with a force with which he should appear dictator over the capital, and through that over the Empire and the Government. The force which he brought with him to Moscow was no longer sufficient for that, as shown in the sequel, but it would have been still less so if, in scattering the Russian Army, he had scattered his own at the same time. Buonaparte was thoroughly alive to all this, and in our eyes he stands completely justified. But on that account this case is still not to be reckoned amongst those in which, through the general relations, the General is interdicted from following up his victory, for there never was in his case any question of mere pursuit. The victory was decided at four o'clock in the afternoon, but the Russians still occupied the greater part of the field of battle; they were not yet disposed to give up the ground, and if the attack had been renewed, they would still have offered a most determined resistance, which would have undoubtedly ended in their complete defeat, but would have cost the conqueror much further bloodshed. We must therefore reckon the Battle of Borodino as amongst battles, like Bautzen, left unfinished. At Bautzen the vanquished preferred to quit the field sooner; at Borodino the conqueror preferred to content himself with a half victory, not because the decision appeared doubtful, but because he was not rich enough to pay for the whole.

Returning now to our subject, the deduction from our reflections in relation to the first stage of pursuit is, that the energy thrown into it chiefly determines the value of the victory; that this pursuit is a second act of the victory, in many cases more important also than the first, and that strategy, whilst here approaching tactics to receive from it the harvest of success, exercises the first act of her authority by demanding this completion of the victory.

But further, the effects of victory are very seldom found to stop with this first pursuit; now first begins the real career to which victory lent velocity. This course is conditioned as we have already said, by other relations of which it is not yet time to speak. But we must here mention, what there is of a general character in the pursuit in order to avoid repetition when the subject occurs again.

In the further stages of pursuit, again, we can distinguish three degrees: the simple pursuit, a hard pursuit, and a parallel march to intercept.

The simple following or pursuing causes the enemy to continue his retreat, until he thinks he can risk another battle. It will therefore in its effect suffice to exhaust the advantages gained, and besides that, all that the enemy cannot carry with him, sick, wounded, and disabled from fatigue, quantities of baggage, and carriages of all kinds, will fall into our hands, but this mere following does not tend to heighten the disorder in the enemy’s Army, an effect which is produced by the two following causes.

If, for instance, instead of contenting ourselves with taking up every day the camp the enemy has just vacated, occupying just as much of the country as he chooses to abandon, we make our arrangements so as every day to encroach further, and accordingly with our advance- guard organised for the purpose, attack his rear-guard every time it attempts to halt, then such a course will hasten his retreat, and consequently tend to increase his disorganisation.--This it will principally effect by the character of continuous flight, which his retreat will thus assume. Nothing has such a depressing influence on the soldier, as the sound of the enemy’s cannon afresh at the moment when, after a forced march he seeks some rest; if this excitement is continued from day to day for some time, it may lead to a complete rout. There lies in it a constant admission of being obliged to obey the law of the enemy, and of being unfit for any resistance, and the consciousness of this cannot do otherwise than weaken the moral of an Army in a high degree. The effect of pressing the enemy in this way attains a maximum when it drives the enemy to make night marches. If the conqueror scares away the discomfited opponent at sunset from a camp which has just been taken up either for the main body of the Army, or for the rear-guard, the conquered must either make a night march, or alter his position in the night, retiring further away, which is much the same thing; the victorious party can on the other hand pass the night in quiet.

The arrangement of marches, and the choice of positions depend in this case also upon so many other things, especially on the supply of the Army, on strong natural obstacles in the country, on large towns, &. &., that it would be ridiculous pedantry to attempt to show by a geometrical analysis how the pursuer, being able to impose his laws on the retreating enemy, can compel him to march at night while he takes his rest. But nevertheless it is true and practicable that marches in pursuit may be so planned as to have this tendency, and that the efficacy of the pursuit is very much enchanced thereby. If this is seldom attended to in the execution, it is because such a procedure is more difficult for the pursuing Army, than a regular adherence to ordinary marches in the daytime. To start in good time in the morning, to encamp at mid-day, to occupy the rest of the day in providing for the ordinary wants of the Army, and to use the night for repose, is a much more convenient method than to regulate one’s movements exactly according to those of the enemy, therefore to determine nothing till the last moment, to start on the march, sometimes in the morning, sometimes in the evening, to be always for several hours in the presence of the enemy, and exchanging cannon shots with him, and keeping up skirmishing fire, to plan manoeuvres to turn him, in short, to make the whole outlay of tactical means which such a course renders necessary. All that naturally bears with a heavy weight on the pursuing Army, and in War, where there are so many burdens to be borne, men are always inclined to strip off those which do not seem absolutely necessary. These observations are true, whether applied to a whole Army or as in the more usual case, to a strong advance-guard. For the reasons just mentioned, this second method of pursuit, this continued pressing of the enemy pursued is rather a rare occurrence; even Buonaparte in his Russian campaign, 1812, practised it but little, for the reasons here apparent, that the difficulties and hardships of this campaign, already threatened his Army with destruction before it could reach its object; on the other hand, the French in their other campaigns have distinguished themselves by their energy in this point also.

Lastly, the third and most effectual form of pursuit is, the parallel march to the immediate object of the retreat.

Every defeated Army will naturally have behind it, at a greater or less distance, some point, the attainment of which is the first purpose in view, whether it be that failing in this its further retreat might be compromised, as in the case of a defile, or that it is important for the point itself to reach it before the enemy, as in the case of a great city, magazines, &., or, lastly, that the Army at this point will gain new powers of defence, such as a strong position, or junction with other corps.

Now if the conqueror directs his march on this point by a lateral road, it is evident how that may quicken the retreat of the beaten Army in a destructive manner, convert it into hurry, perhaps into flight.[*] The conquered has only three ways to counteract this: the first is to throw himself in front of the enemy, in order by an unexpected attack to gain that probability of success which is lost to him in general from his position; this plainly supposes an enterprising bold General, and an excellent Army, beaten but not utterly defeated; therefore, it can only be employed by a beaten Army in very few cases.

[*] This point is exceptionally well treated by von Bernhardi in his “Cavalry in Future Wars.” London: Murray, 1906.

The second way is hastening the retreat; but this is just what the conqueror wants, and it easily leads to immoderate efforts on the part of the troops, by which enormous losses are sustained, in stragglers, broken guns, and carriages of all kinds.

The third way is to make a detour, and get round the nearest point of interception, to march with more ease at a greater distance from the enemy, and thus to render the haste required less damaging. This last way is the worst of all, it generally turns out like a new debt contracted by an insolvent debtor, and leads to greater embarrassment. There are cases in which this course is advisable; others where there is nothing else left; also instances in which it has been successful; but upon the whole it is certainly true that its adoption is usually influenced less by a clear persuasion of its being the surest way of attaining the aim than by another inadmissible motive-- this motive is the dread of encountering the enemy. Woe to the Commander who gives in to this! However much the moral of his Army may have deteriorated, and however well founded may be his apprehensions of being at a disadvantage in any conflict with the enemy, the evil will only be made worse by too anxiously avoiding every possible risk of collision. Buonaparte in 1813 would never have brought over the Rhine with him the 30,000 or 40,000 men who remained after the battle of Hanau,[*] if he had avoided that battle and tried to pass the Rhine at Mannheim or Coblenz. It is just by means of small combats carefully prepared and executed, and in which the defeated army being on the defensive, has always the assistance of the ground--it is just by these that the moral strength of the Army can first be resuscitated.

[*] At Hanau (October 30, 1813), the Bavarians some 50,000 strong threw themselves across the line of Napoleon’s retreat from Leipsic. By a masterly use of its artillery the French tore the Bavarians asunder and marched on over their bodies.--editor.

The beneficial effect of the smallest successes is incredible; but with most Generals the adoption of this plan implies great self-command. The other way, that of evading all encounter, appears at first so much easier, that there is a natural preference for its adoption. It is therefore usually just this system of evasion which best, promotes the view of the pursuer, and often ends with the complete downfall of the pursued; we must, however, recollect here that we are speaking of a whole Army, not of a single Division, which, having been cut off, is seeking to join the main Army by making a de’tour; in such a case circumstances are different, and success is not uncommon. But there is one condition requisite to the success of this race of two Corps for an object, which is that a Division of the pursuing army should follow by the same road which the pursued has taken, in order to pick up stragglers, and keep up the impression which the presence of the enemy never fails to make. Bluecher neglected this in his, in other respects unexceptionable, pursuit after La Belle Alliance.

Such marches tell upon the pursuer as well as the pursued, and they are not advisable if the enemy’s Army rallies itself upon another considerable one; if it has a distinguished General at its head, and if its destruction is not already well prepared. But when this means can be adopted, it acts also like a great mechanical power. The losses of the beaten Army from sickness and fatigue are on such a disproportionate scale, the spirit of the Army is so weakened and lowered by the constant solicitude about impending ruin, that at last anything like a well organised stand is out of the question; every day thousands of prisoners fall into the enemy’s hands without striking a blow. In such a season of complete good fortune, the conqueror need not hesitate about dividing his forces in order to draw into the vortex of destruction everything within reach of his Army, to cut off detachments, to take fortresses unprepared for defence, to occupy large towns, &. &. He may do anything until a new state of things arises, and the more he ventures in this way the longer will it be before that change will take place. is no want of examples of brilliant results from grand decisive victories, and of great and vigorous pursuits in the wars of Buonaparte. We need only quote Jena 1806, Ratisbonne 1809, Leipsic 1813, and Belle- Alliance 1815.