There is no growth of intensity in an attack comparable to that of various types of defense.
The attacker is purchasing advantages that may become valuable at the peace table, but he must pay for them on the spot with his fighting forces. If the superior strength of the attack - which diminishes day by day - leads to peace, the object will have been attained. There are strategic attacks that lead up to the point where their remaining strength is just enough to maintain a defense and wait for peace. Beyond that point the scale turns and the reaction follows with a force that is much stronger than that of the original attack. This is what I mean by the culminating point of the attack.
The natural goal of all campaign plans therefore is the turning point at which the attack becomes defense. If one were to go beyond that point, it would not only be a useless effort which could not add to success. It would in fact be a damaging one. ...
What matters therefore is to detect the culminating point with discriminative judgment.
The obvious answer [in deciding where to stop the attack] is that superior strength is not the end but only the means. The end is either to bring the enemy to his knees or at least to deprive him of some of his territory - the point in that case being not to improve the current military position but to improve one's general prospects in the war and in the peace negotiations. Even if one tries to destroy the enemy completely, one must accept the fact that every step gained may weaken one's superiority - though it does not necessarily follow that it must fall to zero before the enemy capitulates. He may do so at an earlier point, and if this can be accomplished with one's last ounce of superiority, it would be a mistake not to have used it.
This is why the great majority of generals will prefer to stop well short of their objective rather than risk approaching it too closely and why those with high courage and an enterprising spirit will often overshoot it and fail to attain their purpose. Only the man who can achieve great results with limited means [i.e., the military genius] has really hit the mark.
One defensive is not exactly like another, nor will the defense always enjoy the same degree of superiority over attack. In particular this will be the case in a defense that follows directly the exhaustion of an offensive - a defense whose theater of operations is located at the apex of an offensive wedge thrust forward deep into hostile territory . ... It is clear. ... that a defense that is undertaken in the framework of an offensive is weakened in all its key elements. It will thus no longer possess the superiority which basically belongs to it.
It is in the nature of things that a retreat should be continued until the balance of power is reestablished - whether by means of reinforcements or the cover of strong fortresses or major natural obstacles or the overextension of the enemy. The magnitude of the losses, the extent of the defeat, and, what is even more important, the nature of the enemy, will determine how soon the moment of equilibrium will return.
Once the defender has gained an important advantage, defense as such has done its work. While he is enjoying this advantage, he must strike back, or he will court destruction. Prudence bids him strike while the iron is hot and use the advantage to prevent a second onslaught. How, when, and where that reaction is to begin depends, of course, on many other conditions which we shall detail subsequently. For the moment, we shall simply say that this transition to the counterattack must be accepted as a tendency inherent in defense - indeed, as one of its essential features. Wherever a victory achieved by the defensive form is not turned to military account, where, so to speak, it is allowed to wither away unused, a serious mistake is being made. A sudden powerful transition to the offensive - the flashing sword of vengeance - is the greatest moment for the defense.
While we [i.e., the defender deep in the interior of his country] may have more time and can wait until the enemy is at last at his weakest, the assumption will remain that we shall have to take the initiative at the end. ... so long as the defender's strength increases every day while the attacker's diminishes, the absence of decision is the former's best interest; ... the point of culmination will necessarily be reached when the defender must make up his mind and act , when the advantages of waiting have been completely exhausted. There is of course no infallible means of telling when that point has come; a great many conditions and circumstances may determine it.
The decision on the terminal point for retreat should depend on the situation as a whole. It is wrong to decide on a place which, considered in relation to only part of the situation, appears to be favourable for our passing to the counter-offensive, for at the start of our counter-offensive, we must take subsequent developments into consideration, and our counter-offensives always begin on a partial scale.
A well-timed retreat, which enables us to keep all the initiative, is of great assistance to us in switching to the counter-offensive, when we have reached the terminal point of retreat, we have regrouped our forces, and are waiting at our ease for the fatigued enemy.
The first covers the period of the enemy's strategic offensive and our strategic defensive. The second stage will be the period of the enemy's strategic consolidation and our preparations for the counter-offensive. The third stage will be the period of our strategic counter-offensive and the enemy's retreat. It is impossible to predict the concrete situation in the three stages. ... [in which] the objective course of events will be exceedingly rich and varied with many twists and turns. ...
The enemy advances, we retreat;
The enemy camps, we harass;
The enemy tires, we attack;
The enemy retreats, we pursue.