On War

Carl von Clausewitz, Michael Howard, Peter Paret

• Publisher: Princeton University Press
• Year: 2008
• ISBN:
  9781400837403
• Topic: History
• Subtopic: Military & Maritime History
• Index: History

The most authoritative and feature-rich edition of On War in English Carl von Clausewitz's On War is the most significant attempt in Western history to understand war, both in its internal dynamics and as an instrument of policy. Since the work's first appearance in 1832, it has been read throughout the world, and has stimulated generations of soldiers, political leaders, and intellectuals. First published in 1976 and revised in 1984, Michael Howard and Peter Paret's Princeton edition of Clausewitz's classic work has itself achieved classic status and is widely regarded as the best translation and standard edition of On War in English. This feature-rich edition includes an essay by Paret on the genesis of Clausewitz's book, an essay by Howard on Clausewitz's influence, and an essay by Bernard Brodie on the continuing relevance of On War. In addition, Brodie provides a lengthy and detailed commentary on and guide to reading On War, and the edition also includes a comprehensive index.

BOOK SIX

Defense

CHAPTER ONE

Attack and Defense

I. THE CONCEPT OF DEFENSE

What is the concept of defense? The parrying of a blow. What is its characteristic feature? Awaiting the blow. It is this feature that turns any action into a defensive one; it is the only test by which defense can be distinguished from attack in war. Pure defense, however, would be completely contrary to the idea of war, since it would mean that only one side was waging it. Therefore, defense in war can only be relative, and the characteristic feature of waiting should be applied only to the basic concept, not to all of its components. A partial engagement is defensive if we await the advance, the charge of the enemy. A battle is defensive if we await the attack—await, that is, the appearance of the enemy in front of our lines and within range. A campaign is defensive if we wait for our theater of operations to be invaded. In each of these cases the characteristic of waiting and parrying is germane to the general idea without being in conflict with the concept of war; for we may find it advantageous to await the charge against our bayonets and the attack on our position and theater of operations. But if we are really waging war, we must return the enemy's blows; and these offensive acts in a defensive war come under the heading of “defense”—in other words, our offensive takes place within our own positions or theater of operations. Thus, a defensive campaign can be fought with offensive battles, and in a defensive battle, we can employ our divisions offensively. Even in a defensive position awaiting the enemy assault, our bullets take the offensive. So the defensive form of war is not a simple shield, but a shield made up of well-directed blows.

2. ADVANTAGES OF DEFENSE

What is the object of defense? Preservation. It is easier to hold ground than take it. It follows that defense is easier than attack, assuming both sides have equal means. Just what is it that makes preservation and protection so much easier? It is the fact that time which is allowed to pass unused accumulates to the credit of the defender. He reaps where he did not sow. Any omission of attack—whether from bad judgment, fear, or indolence—accrues to the defenders' benefit. This saved Prussia from disaster more than once during the Seven Years War. It is a benefit rooted in the concept and object of defense: it is in the nature of all defensive action. In daily life, and especially in litigation (which so closely resembles war) it is summed up by the Latin proverb beati sunt possidentes. Another benefit, one that arises solely from the nature of war, derives from the advantage of position, which tends to favor the defense.

Having outlined these general concepts, we now turn to the substance.

Tactically, every engagement, large or small, is defensive if we leave the initiative to our opponent and await his appearance before our lines. From that moment on we can employ all offensive means without losing the advantages of the defensive—that is to say the advantages of waiting and the advantages of position. At the strategic level the campaign replaces the engagement and the theater of operations takes the place of the position. At the next stage, the war as a whole replaces the campaign, and the whole country the theater of operations. In both cases, defense remains the same as at the tactical level.

We have already indicated in general terms that defense is easier than attack. But defense has a passive purpose: preservation; and attack a positive one: conquest. The latter increases one's own capacity to wage war; the former does not. So in order to state the relationship precisely, we must say that the defensive form of warfare is intrinsically stronger than the offensive. This is the point we have been trying to make, for although it is implicit in the nature of the matter and experience has confirmed it again and again, it is at odds with prevalent opinion, which proves how ideas can be confused by superficial writers.

If defense is the stronger form of war, yet has a negative object, it follows that it should be used only so long as weakness compels, and be abandoned as soon as we are strong enough to pursue a positive object. When one has used defensive measures successfully, a more favorable balance of strength is usually created; thus, the natural course in war is to begin defensively and end by attacking. It would therefore contradict the very idea of war to regard defense as its final purpose, just as it would to regard the passive nature of defense not only as inherent in the whole but also in all its parts. In other words, a war in which victories were used only defensively without the intention of counterattacking would be as absurd as a battle in which the principle of absolute defense—passivity, that is—were to dictate every action.

The soundness of this general idea could be challenged by citing many examples of wars in which the ultimate purpose of defense was purely defensive, without any thought being given to a counteroffensive. This line of argument would be possible if one forgot that a general concept is under discussion. The examples that could be cited to prove the opposite must all be classed as cases in which the possibility of a counteroffensive had not yet arisen.

In the Seven Years War, for instance, Frederick the Great had no thought of taking the offensive, at least not in its final three years. Indeed, we believe that in this war he always regarded offensives solely as a better means of defense. This attitude was dictated by the general situation; and it is natural for a commander to concentrate only on his immediate needs. Nevertheless one cannot look at this example of defense on a grand scale without speculating that the idea of a possible counteroffensive against Austria may have been at the root of it, and conclude that the time for such a move had not yet come. The peace that was concluded proves that this was not an empty assumption: What else could have induced the Austrians to make peace but the thought that their forces could not on their own outweigh the genius of the King; that in any case they would have to increase their efforts; and that any relaxation was almost bound to cost them further territory? And, indeed, is there any doubt that Frederick would have tried to crush the Austrians in Bohemia and Moravia again if Russia, Sweden, and the Army of the Empire had not diverted his energies?

Now that we have defined the concept of defense and have indicated its limits, we return once more to our claim that defense is the stronger form of waging war.

Close analysis and comparison of attack and defense will prove the point beyond all doubt. For the present, we shall merely indicate the inconsistencies the opposite view involves when tested by experience. If attack were the stronger form, there would be no case for using the defensive, since its purpose is only passive. No one would want to do anything but attack: defense would be pointless. Conversely, it is natural that the greater object is bought by greater sacrifice. Anyone who believes himself strong enough to employ the weaker form, attack, can have the higher aim in mind; the lower aim can only be chosen by those who need to take advantage of the stronger form, defense. Experience shows that, given two theaters of operations, it is practically unknown for the weaker army to attack and the stronger stay on the defensive. The opposite has always happened everywhere, and amply proves that commanders accept defense as the stronger form, even when they personally would rather attack.

Some related points remain to be discussed in the following chapters.

CHAPTER TWO

The Relationship between Attack and Defense in Tactics

First let us examine the factors that lead to victory in an engagement.

At this stage we are not concerned with numerical superiority, courage, training, or other qualities of an army. All of these as a rule depend on matters beyond that part of the art of war we are concerned with here; in any case their bearing would be the same on attack and defense. Even general superiority of numbers is not relevant, since numbers, too, are usually a given quantity in which a commander has no say. Moreover, these matters have no special bearing on attack and defense. Only three things seem to us to produce decisive advantages: surprise, the benefit of terrain, and concentric attack.

Surprise becomes effective when we suddenly face the enemy at one point with far more troops than he expected. This type of numerical superiority is quite distinct from numerical superiority in general: it is the most powerful medium in the art of war. The ways in which the advantage of terrain contributes toward victory are fairly obvious. But it should be noted that this is more than a matter of obstacles to an attack—steep slopes, high mountains, marshy streams, hedges, and the like. Terrain may be just as useful by enabling us to hold a concealed position; even a featureless landscape can provide some advantage to those familiar with it. Concentric attack comprises all tactical envelopment, great or small; its effectiveness is produced partly by the double effectiveness of cross fire, and partly by the fear of being cut off.

What is the relationship of attack and defense to these matters?

Bearing in mind the three elements of victory already described, the answer must be this: the attacker is favored by only a small part of the first and third factors while their larger part, and the second factor exclusively, are available to the defender.

The one advantage the attacker possesses is that he is free to strike at any point along the whole line of defense, and in full force: the defender, on the other hand, is able to surprise his Opponent constantly throughout the engagement by the strength and direction of his counterattacks.

For the attacker it is easier to surround the whole opposing force and cut it off than it is for the defender: the latter is tied to his position and has thereby presented the attacker with an objective. But the attacker's envelopment and its advantage is applicable only to the whole position, for in the course of the engagement, it is easier for the defender to attack segments of the opposite force concentrically; for as we have already said, the defender is better placed to spring surprises by the strength and direction of his own attacks.

It is self-evident that it is the defender who primarily benefits from the terrain. His superior ability to produce surprise by virtue of the strength and direction of his own attack stems from the fact that the attack has to approach on roads and paths on which it can easily be observed; the defender's position, on the other hand, is concealed and virtually invisible to his opponent until the decisive moment arrives. Ever since the right method of defense was adopted, reconnaissance has gone out of fashion—or, rather, it has become impossible. Some reconnaissance is still carried out now and again, but as a rule nothing much comes of it. And yet, no matter how great the advantage of being free to choose the ground for a position and become familiar with it before the action, and no matter how plain it is that the defender in the concealed position he has selected is bound to cause far more surprise than the attacker, the older view persists: a battle accepted is regarded as already half lost. This stems from the type of defense that was practiced twenty years ago and to some extent in the Seven Years War as well. In those days the only kind of advantage looked for in terrain was that the front had to be difficult to approach (because of steep slopes, etc.). The shallowness of the positions and the difficulties of maneuvering one's flanks made armies so weak that they had to dodge each other from hill to hill and so made things even worse. Once some kind of support had been secured, the army was stretched as tight as on an embroidery frame: all depended on its not being pierced. The defended terrain was considered valuable for its own sake, and so had to be defended at all points. Thus movement or surprise in battle were out of the question. This was the complete opposite of what a good defense can be, and in fact has been in the recent past.

Defense appears to fall into disrepute whenever a particular style of it has become obsolescent; that is what happened in the case described above. In its day this method of defense really had been superior to the attack.

If we survey the development of modern war, we find that at the beginning—in the Thirty Years War and the War of the Spanish Succession—an army's deployment and disposition was one of the main elements in a battle. It was the most important part of the plan of action. This normally worked to the advantage of the defender because his forces were deployed and in position from the start. With the troops' increased ability to maneuver, this advantage was lost, and for a time the attack gained the upper hand. The defender now sought protection behind rivers or deep valleys, or on mountains. He thus recovered a distinct advantage, which lasted until the attacker became so mobile and so skilled that he could venture even into rough country and attack in separate columns; which enabled him to turn the enemy. This led to greater and greater extension of the line of battle until it naturally occurred to the attacker to concentrate on a limited number of points and pierce the enemy's shallow position. Thus the offensive gained the upper hand for the third time, and once again the defensive had to change its methods. That is what happened in the recent wars. Forces were kept concentrated in large masses, most of them not deployed and, wherever possible, in concealed positions. The object was simply to be ready to deal with the attack as soon as its intentions became clear.

This does not entirely preclude defending one's ground in a partly passive manner, for to do so offers such decisive advantages that it is frequently done in the course of a campaign. But usually the passive defense of terrain is no longer dominant—which is all we are concerned with here.

If the offensive were to invent some major new expedient—which is unlikely in view of the simplicity and inherent necessity that marks everything today—the defensive will also have to change its methods. But it will always be certain of having the benefit of terrain, and this will generally ensure its natural superiority; for today the peculiarities of the topography and the ground have a greater effect on military action than ever.

CHAPTER THREE

The Relationship between Attack and Defense in Strategy

Let us again begin by examining the factors that assure strategic success.

As we have said before, in strategy there is no such thing as victory. Part of strategic success lies in timely preparation for a tactical victory; the greater the strategic success, the greater the likelihood of a victorious engagement. The rest of strategic success lies in the exploitation of a victory won. The more strategy has been able, through its ingenuity, to exploit a victorious battle; the more that it can wrest out of the collapsing edifice whose foundations have been shattered by the action; the more completely the fruits of the hard-won victory can be harvested; then the greater the success. The main factors responsible for bringing about or facilitating such a success—thus the main factors in strategic effectiveness—are the following:

1. The advantage of terrain

2. Surprise—either by actual assault or by deploying unexpected strength at certain points

3. Concentric attack (all three as in tactics)

4. Strengthening the theater of operations, by fortresses, with all they involve

5. Popular support

6. The exploitation of moral factors.¹

What is the relationship of attack and defense with regard to these factors?

In strategy as well as in tactics, the defense enjoys the advantage of terrain, while the attack has the advantage of initiative.² As regards surprise and initiative, however, it must be noted that they are infinitely more important and effective in strategy than in tactics. Tactical initiative can rarely be expanded into a major victory, but a strategic one has often brought the whole war to an end at a stroke. On the other hand, the use of this device assumes major, decisive, and exceptional mistakes on the enemy's part. Consequently it will not do much to tip the scales in favor of attack.

Surprising the enemy by concentrating superior strength at certain points is again comparable to the analogous case in tactics. If the defender were compelled to spread his forces over several points of access, the attacker would obviously reap the advantage of being able to throw his full strength against any one of them.

Here too the new system of defense has, by its new approach, imperceptibly introduced new principles. Where the defender has no reason to fear that his opponent will be able by advancing along an undefended road to seize an important depot or munitions dump, or take a fortress unawares, or even the capital unawares; where, therefore, he is not forced to attack the enemy on the road chosen by the latter in order to avoid having his retreat cut off; then there is no reason for him to split his forces. If the attacker chooses a road on which he does not expect to meet the defender, the latter can still seek him out there with his entire strength a few days later. Indeed he can be sure that in most cases the attacker himself will oblige him by seeking him out. But if for some reason the attacker has to advance with divided forces—and problems of supply often leave him little choice—the defender obviously reaps the benefit of being able to attack a part of his opponent with his own full strength.

In strategy, the nature of flank and rear attacks on a theater of operations changes to a significant degree.

1. The effect of cross fire is eliminated, since one cannot fire from one end of a theater of operations to the other.

2. There is less fear of being cut off, since whole areas cannot be sealed off in strategy as they can in tactics.

3. Because of the greater areas involved in strategy, the effectiveness of interior and therefore shorter lines is accentuated and forms an important counterbalance against concentric attacks.

4. A new factor emerges in the vulnerability of lines of communication, that is, in the consequences of their being cut.

Because of the greater areas involved in strategy, envelopment or concentric attack will of course only be possible for the side which takes the initiative—in other words, the attacker. The defender cannot, as he can in tactics, surround the surrounder in turn, for he cannot deploy his troops in the relative depth required, nor keep them sufficiently concealed. But what use to the attack is ease of envelopment if its rewards do not materialize? In strategy, therefore, there would be no justification at all in putting forward the enveloping attack as a means of victory, were it not for its effect on lines of communication. Yet this is seldom an important factor at the earliest stage when attack is first confronted by defense, and the two sides face each other in their opening positions. It only begins to tell in the course of a campaign, when the attacker, in enemy territory, gradually becomes the defender. At that point the new defender finds his lines of communication weakening, and the original defender can exploit that weakness once he has taken the offensive. But it must be obvious that as a rule the defender deserves no credit for this advantage, since it really derives from the principles inherent in the defense itself.

The fourth element, the advantages of the theater of operations, naturally benefit the defender. By initiating the campaign, the attacking army cuts itself off from its own theater of operations, and suffers by having to leave its fortresses and depots behind. The larger the area of operations that it must traverse, the more it is weakened—by the effect of marches and by the detachment of garrisons. The defending army, on the other hand, remains intact. It benefits from its fortresses, nothing depletes its strength, and it is closer to its sources of supply.

The support of the population, the fifth principle, will not necessarily apply to every defense; a defensive campaign may be fought in enemy territory. Still, this element derives from the concept of defense alone, and it is applicable in the vast majority of cases. What is meant is primarily (but not exclusively) the effectiveness of militia, and arming the population. Furthermore, every kind of friction is reduced, and every source of supply is nearer and ...