Principles of War, by Carl von Clausewitz (Part III)
III. STRATEGYThis term means the combination of individual engagements to attain the goal of the campaign or war.
If we know how to fight and how to win, little more knowledge is needed. For it is easy to combine fortunate results. It is merely a matter of experienced judgment and does not depend on spe- cial knowledge, as does the direction of battle.
The few principles, therefore, which come up in this connection, and which depend primarily on the condition of the respective states and armies, can in their essential parts be very briefly summarized:
I. Warfare has three main objects:
(a) To conquer and destroy the armed power of the enemy;
(b) To take possession of his material and other sources of strength, and
(c) To gain public opinion.
2. To accomplish the first purpose, we should always direct our principal operation against the main body of the enemy army or at least against an important portion of his forces. For only after defeating these can we pursue the other two objects successfully.
3. In order to seize the enemy’s material forces we should direct our operations against the places where most of these resources are concentrated: principal cities, storehouses, and large fortresses. On the way to these objectives we shall encounter the enemy’s main force or at least a considerable part of it.
4. Public opinion is won through great victories and the occupation of the enemy’s capital.
5. The first and most important rule to observe in order to accomplish these purposes, is to use our entire forces with the utmost energy. Any moderation shown would leave us short of our aim. Even with everything in our favor, we should be unwise not to make the greatest effort in order to make the result perfectly certain. For such effort can never produce negative results. Suppose the country suffers greatly from this, no lasting dis- advantage will arise; for the greater the effort, the sooner the suffering will cease.
The moral impression created by these actions is of infinite importance. They make everyone confident of success, which is the best means for suddenly raising the nation’s morale.
6. The second rule is to concentrate our power as much as possible against that section where the chief blows are to be delivered and to incur disadvantages elsewhere, so that our chances of success may increase at the decisive point. This will compensate for all other disadvantages.
7. The third rule is never to waste time. Unless important advantages are to be gained from hesitation, it is necessary to set to work at once. By this speed a hundred enemy measures are nipped in the bud, and public opinion is won most rapidly.
Surprise plays a much greater role in strategy than in tactics. It is the most important element of victory. Napoleon, Frederick II, Gustavus Adolphus, Caesar, Hannibal, and Alexander owe the brightest rays of their fame to their swiftness.
8. Finally, the fourth rule is to follow up our successes with the utmost energy. Only pursuit of the beaten enemy gives the fruits of victory.
9. The first of these rules serves as a basis for the other three. If we have observed it, we can be as daring as possible with the last three, and yet not risk our all. For it provides us with the means of constantly creating new forces in our rear, and with fresh forces any misfortune can be remedied.
Therein lies the caution which deserves to be called wise, and not in taking each step forward with timidity.
10. Small states cannot wage wars of conquest in our times. But in defensive warfare even the means of small states are infinitely great. I am, therefore, firmly convinced that if we spare no effort to reappear again and again with new masses of troops, if we use all possible means of preparation and keep our forces concentrated at the main point, and if we, thus prepared, pursue a great aim with determination and energy, we have done all that can be done on a large scale for the strategic direction of the war. And unless we are very unfortunate in battle we are bound to be victorious to the same extent that our opponent lags behind in effort and energy.
11. In observing these principles little depends on the form in which the operations are carried out. I shall try, nevertheless, to make clear in a few words the most important aspects of this question.
In tactics we always seek to envelop that part of the enemy against which we direct our main attack. We do this partly because our forces are more effective in a concentric than in a parallel attack, and further because we can only thus cut off the enemy from his line of retreat.
But if we apply this to the whole theater of war (and consequently to the enemy’s lines of communication), the individual columns and armies, which are to envelop the enemy, are in most cases too far away from each other to participate in one and the same engagement. The opponent will find himself in the middle and will be able to turn against the corps one by one and defeat them all with a single army. Frederick II’s campaigns may serve as examples, especially those of 1757 and 1758.*12
The individual engagement, therefore, remains the principal decisive event. Consequently, if we attack concentrically without having decisive superiority, we shall lose in battle all the advantages, which we expected from our enveloping attack on the enemy. For an attack on the lines of communication takes effect only very slowly, while victory on the field of battle bears fruit immediately.
In strategy, therefore, the side that is surrounded by the enemy is better off than the side which surrounds its opponent, especially with equal or even weaker forces.
Colonel Jomini was right in this, and if Mr. von Bülow has demonstrated the opposite with so much semblance of truth, it is only because he attributed too great an importance to the inter- ruption of provisions and carelessly and completely denied the inevitable success of battle.*13
To cut the enemy’s line of retreat, however, strategic envelopment or a turning movement is very effective. But we can achieve this, if necessary, through tactical envelopment. A strategic move is, therefore, advisable only if we are so superior (physically and morally) that we shall be strong enough at the principal point to dispense with the detached corps.
The Emperor Napoleon never engaged in strategic envelopment, although he was often, indeed almost always, both physically and morally superior.*14
Frederick II used it only once, in 1757, in his invasion of Bohemia.*15 To be sure, the result was that the Austrians could not give battle until Prague, and what good was the conquest of Bohemia as far as Prague without a decisive victory? The battle of Kolin forced him to give up all this territory again, which proves that battles decide everything. At the same time he was obviously in danger at Prague of being attacked by the whole Austrian force, before Schwerin arrived. He would not have run this risk had he passed through Saxony with all his forces. In that case the first battle would have been fought perhaps near Budin, on the Eger, and it would have been as decisive as that of Prague. The dislocation of the Prussian army during the winter in Silesia and Saxony undoubtedly caused this concentric maneuver. It is important to notice that circumstances of this kind are generally more influential than the advantages to be gained by the form of attack. For facility of operations increases their speed, and the friction inherent in the tremendous war-machine of an armed power is so great in itself that it should not be increased unnecessarily.
12. Moreover, the principle of concentrating our forces as much as possible on the main point diverts us from the idea of strategic envelopment and the deployment of our forces follows automatically. I was right, therefore, in saying that the form of this deployment is of little consequence. There is, however, one case in which a strategic move against the enemy’s flank will lead to great successes similar to those of a battle: if in a poor country the enemy has accumulated with great effort stores of supplies, on whose preservation his operations absolutely depend. In this case it may be advisable not to march our main forces against those of the enemy, but to attack his base of supply. For this, however, two conditions are essential:
(a) The enemy must be so far from his base that our threat will force him into a considerable retreat, and
(b) We must be able to obstruct his advance in the direction followed by his principal force with only a few troops (thanks to natural and artificial obstacles), so that he cannot make conquests somewhere else which will compensate for the loss of his base.
13. The provisioning of troops is a necessary condition of warfare and thus has great influence on the operations, especially since it permits only a limited concentration of troops and since it helps to determine the theater of war through the choice of a line of operations.
14. The provisioning of troops is carried on, if a region possibly permits it, through requisitions at the expense of the region.
In the modern method of war armies take up considerably more territory than before. The creation of distinct, independent corps has made this possible, without putting ourselves at a disadvantage before an adversary who follows the old method of concentration at a single point (with from 70,000 to 100,000 men). For an independent corps, organized as they now are, can withstand for some time an enemy two or three times its superior. Then the others will arrive and, even if the first corps has already been beaten, it has not fought in vain, as we have had occasion to remark.
Today, therefore, the divisions and corps move into battle independently, marching side by side or behind each other and only close enough to take part in the same battle, if they belong to the same army.
This makes possible immediate provisioning without storehouses. The very organization of the corps with their General Staff and their Commissariat facilitates this.
5. If there are no MORE decisive motives (as for example the location of the enemy’s main army), we choose the most fertile provinces for our operations; for facility of provisioning increases the speed of our actions. Only the situation of the enemy’s main force which we are seeking out, only the location of his capital and the place of arms which we wish to conquer are more important than provisioning. All other considerations, such as the advantageous disposition of our forces, of which we have already spoken, are as a rule much less important.
16. In spite of these new methods of provisioning, it is quite impossible to do without any depots whatever. Therefore, even when the resources of the region are quite sufficient, a wise military leader does not fail to establish depots in his rear for unexpected emergencies and in order to be able to concentrate his forces at certain points. This precaution is of the sort which are not taken at the expense of the final goal.
1. Politically speaking defensive war is a war which we wage for our independence. Strategically it is the kind of campaign in which we limit ourselves to fighting the enemy in a theater of war which we have prepared for this purpose. Whether the battles which we wage in this theater of war are offensive or defensive, makes no difference.
2. We adopt a strategic defensive mainly when the enemy is superior. Fortresses and entrenched camps, which constitute the chief preparations for a theater of war, afford, of course, great advantages, to which may be added the knowledge of the terrain and the possession of good maps. A smaller army, or an army which is based on a smaller state and more limited resources, will be better able to withstand the enemy WITH these advantages than without them.
In addition there are the following two reasons which can lead us to choose a defensive war.
First, when the regions surrounding the theater of war render operations extremely difficult because of lack of provisions. In this case we avoid a disadvantage which the enemy is forced to un- dergo. This is the case now (1812) with the Russian army.
Second, when the enemy is superior in warfare. In a theater of war which we have prepared, which we know, and in which all minor conditions are in our favor, war is easier to conduct, and we com- mit fewer mistakes. When lack of trust in our troops and generals forces us to wage defensive war, we often like to combine tactical with strategic defensive. In that case we fight battles in prepared positions because we are thus again exposed to fewer mistakes.
3. In defensive just as in offensive warfare, it is necessary to pursue a great aim: the destruction of the enemy army, either by battle or by rendering its subsistence extremely difficult. Thus we shall disorganize it and force it into a retreat, during which it will necessarily suffer great losses. Wellington’s campaign in 1810 and 1811 is a good example.*16
Defensive warfare, therefore, does not consist of waiting idly for things to happen. We must wait only if it brings us visible and decisive advantages. That calm before the storm, when the aggressor is gathering new forces for a great blow, is most dangerous for the defender.
If the Austrians after the battle of Aspern had increased their forces threefold, as they might have and as the Emperor Napoleon did, then and only then would they have made good use of the lull which lasted until the battle of Wagram. This they did not do, and consequently the time was lost. It would have been wiser to profit from Napoleon’s disadvantageous position, and to gather the fruits of the battle of Aspern.*17
4. The purpose of fortifications is to keep a considerable part of the enemy’s army occupied as siege troops, to give us an opportunity to defeat the rest of his army. Consequently, it is best to fight our battles behind our fortifications and not in front of them. But we must not stand by idly, while they are being conquered, as Bennigsen did during the siege of Danzig.*18
5. Large rivers, across which it is difficult to throw a bridge (such as the Danube below Vienna and the Lower Rhine), offer a natural line of defense. But we should not distribute our forces evenly along the river bank in order to prevent any crossing whatsoever. That would be most dangerous. On the contrary, we should watch the river and fall upon the enemy from all sides the minute he crosses, while he has not yet reassembled his forces and is still restricted to a narrow space on the river bank. The battle of Aspern offers a good illustration. At Wagram the Austrians had yielded to the French too much territory without the slightest necessity, so that the disadvantages inherent in a river crossing had disappeared.*19
6. Mountains are the second obstacle which offers a good line of defense. There are two ways of using them. The first is to leave them in front of us, occupying them only with light troops and considering them, so to speak, a river which the enemy will have to cross. As soon as his separated columns emerge from the passes, we fall upon one of them with all our force. The second is to occupy the mountains ourselves. In that case we must defend each pass with just a small corps and keep an important part of the army (1/3-1/2) in reserve, in order to attack with superior forces one of the enemy columns that succeed in breaking through. We must not divide up this large reserve to prevent completely the penetration of any enemy columns, but must plan from the outset to fall only upon those columns which we suppose to be the strongest. If we thus defeat an important part of the attacking army, any other columns which have succeeded in breaking through will withdraw of their own accord.
In the midst of most mountain formations we find more or less elevated plains (plateaus) whose slopes are cut by ravines serving as means of access. Mountains, therefore, offer the defender a region in which he can move rapidly to the right or left, while the columns of the aggressor remain separated by steep, inaccessible ridges. Only mountains of this kind are well adapted for defensive warfare. If, on the other hand, their whole interior is rough and inaccessible, leaving the defender dispersed and divided, their defense by the bulk of the army is a dangerous undertaking. For under these circumstances all advantages are on the side of the aggressor, who can attack certain points with great superiority, and no pass, no isolated point is so strong that it cannot be taken within a day by superior forces.
7. In regard to mountain warfare in general, we should observe that everything depends on the skill of our subordinate officers and still more on the morale of our soldiers. Here it is not a question of skillful maneuvering, but of warlike spirit and whole- hearted devotion to the cause; for each man is left more or less to act independently. That is why national militias are especially suited for mountain warfare. While they lack the ability to maneuver, they possess the other qualities to the highest degree.
8. Finally, it should be observed that the strategic defensive, though it is stronger than the offensive, should serve only to win the first important successes. If these are won and peace does not follow immediately, we can gain further successes only through the offensive. For if we remain continually on the defensive, we run the great risk of always waging war at our own expense. This no state can endure indefinitely. If it submits to the blows of its adversary without ever striking back, it will very likely become exhausted and succumb. We must begin, therefore, using the defensive, so as to end more successfully by the offensive.
1. The strategic offensive pursues the aim of the war directly, aiming straight at the destruction of the enemy’s forces, while the strategic defensive seeks to reach this purpose indirectly. The principles of the offensive are therefore already contained in the “General Principles” of strategy. Only two points need be mentioned more fully.
2. The first is constant replacement of troops and arms. This is easier for the defender, because of the proximity of his sources of supply. The aggressor, although he controls in most cases a larger state, must usually gather his forces from a distance and therefore with great difficulty. Lest he find himself short of effectives, he must organize the recruiting of troops and the transport of arms a long time before they are needed. The roads of our lines of operation must be covered constantly with transports of soldiers and supplies. We must establish military stations along these roads to hasten this rapid transport.
3. Even under the most favorable circumstances and with greatest moral and physical superiority, the aggressor should foresee a possibility of great disaster. He therefore must organize on his lines of operation strong points to which he can retreat with a defeated army. Such are fortresses with fortified camps or simply fortified camps.
Large rivers offer the best means of halting the pursuing enemy for a while. We must therefore secure our crossing by means of bridgeheads, surrounded by a number of strong redoubts.
We must leave behind us a number of troops for the occupation of these strong points as well as the occupation of the most important cities and fortresses. Their number depends on how much we have to be afraid of invasions or of the attitude of the inhabitants. These troops, together with reinforcements, form new corps, which, in case of success, follow the advancing army, but in case of misfortune, occupy the fortified points in order to secure our retreat.
Napoleon always took great care with these measures for the protection of the rear of his army, and therefore, in his most audacious operations, risked less than was usually apparent.