There is, therefore, in strategy, in the use of the theatre of war as well as in everything else, an economy of force; the less one can make suffice the better: but there must be sufficient, and here, as well as in commerce, there is something to be thought of besides mere niggardliness.
But in order to prevent a great misconception, we must draw attention to this, that the subject of our present consideration is not how much resistance an army can offer, or the enterprises which it can undertake after a lost battle, but only the result which we can promise ourselves beforehand from this second act in our defence; consequently, how high we can estimate it in our plan. Here there is only one point almost which the defender has to look to, which is the character and the situation of his opponent. An adversary weak in character, with little self-confidence, without noble ambition, placed under great restrictions, will content himself, in case he is successful, with a moderate advantage, and timidly hold back at every fresh offer of a decision which the defender ventures to make. In this case the defender may count upon the beneficial use of all the means of resistance of his theatre of war in succession, in constantly fresh, although in themselves small, combats, in which the prospect always brightens of an ultimate decision in his favour.
But who does not feel that we are now on the road to campaigns devoid of decision, which are much more the field of a successive application of force. Of these we shall speak in the following chapter.
CHAPTER XXX.
Defence of a Theatre of War (continued)
When no Decision is Sought for.
Whether and how far a war is possible in which neither party acts on the offensive, therefore in which neither combatant has a positive aim, we shall consider in the last book; here it is not necessary for us to occupy ourselves with the contradiction which this presents, because on a single theatre of war we can easily suppose reasons for such a defensive on both sides, consequent on the relations of each of these parts to a whole.
But in addition to the examples which history furnishes of particular campaigns that have taken place without the focus of a necessary solution, history also tells us of many others in which there was no want of an assailant, consequently no want of a positive will on one side, but in which that will was so weak that instead of striving to attain the object at any price, and forcing the necessary decision, it contented itself with such advantages as arose in a manner spontaneously out of circumstances. Or the assailant pursued no self-selected end at all, but made his object depend on circumstances, in the meanwhile gathering such fruits as presented themselves from time to time.
Although such an offensive which deviates very much from the strict logical necessity of a direct march towards the object, and which, almost like a lounger sauntering through the campaign, looking out right and left for the cheap fruits of opportunity, differs very little from the defensive itself, which allows the general to pick up what he can in this way, still we shall give the closer philosophical consideration of this kind of warfare a place in the book on the attack. Here we shall confine ourselves to the conclusion that in such a campaign the settlement of the whole question is not looked for by either assailant or defender through a decisive battle, that, therefore, the great battle is no longer the key-stone of the arch, towards which all the lines of the strategic superstructure are directed. Campaigns of this kind (as the history of all times and all countries shows us) are not only numerous, but form such an overwhelming majority, that the remainder only appear as exceptions. Even if this proportion should alter in the future, still it is certain that there will always be many such campaigns; and, therefore, in studying the theory of the defence of a theatre of war, they must be brought into consideration. We shall endeavour to describe the peculiarities by which they are characterised. Real war will generally be in a medium between the two different tendencies, sometimes approaching nearer to one, sometimes to the other, and we can, therefore, only see the practical effect of these peculiarities in the modification which is produced, in the absolute form of war by their counteraction. We have already said in the third chapter of this book, that the state of expectation is one of the greatest advantages which the defensive has over the offensive; as a general rule, it seldom happens in life, and least of all in war, that all that circumstances would lead us to expect does actually take place. The imperfection of human insight, the fear of evil results, accidents which derange the development of designs in their execution, are causes through which many of the transactions enjoined by circumstances are never realised in the execution. In war where insufficiency of knowledge, the danger of a catastrophe, the number of accidents are incomparably greater than in any other branch of human activity, the number of shortcomings, if we may so call them, must necessarily also be much greater. This is then the rich field where the defensive gathers fruits which grow for it spontaneously. If we add to this result of experience the substantial importance of the possession of the surface of the ground in war, then that maxim which has become a proverb, beati sunt possidentes, holds good here as well as in peace. It is this maxim which here takes the place of the decision, that focus of all action in every war directed to mutual destruction. It is fruitful beyond measure, not in actions which it calls forth, but in motives for not acting, and for all that action which is done in the interest of inaction. When no decision is to be sought for or expected, there is no reason for giving up anything, for that could only be done to gain thereby some advantage in the decision. The consequence is that the defender keeps all, or at least as much as he can (that is as much as he can cover), and the assailant takes possession of so much as he can without involving himself in a decision, (that is, he will extend himself laterally as much as possible). We have only to deal with the first in this place.
Wherever the defender is not present with his military forces, the assailant can take possession, and then the advantage of the state of expectation is on his side; hence the endeavour to cover the country everywhere directly, and to take the chance of the assailant attacking the troops posted for this purpose.
Before we go further into the special properties of the defence, we must extract from the book on the attack those objects which the assailant usually aims at when the decision (by battle) is not sought. They are as follows:—
1. The seizure of a considerable strip of territory, as far as that can be done without a decisive engagement.