On War

by Carl von Clausewitz

But now the close relationship between this essence of a militia system, and the conception of the defensive, is not to be denied, neither can it be denied that such a militia will always belong more to the defensive form than to the offensive, and that it will manifest chiefly in the defensive, those effects through which it surpasses the attack.

2.—Fortresses.

The assistance afforded by fortresses to the offensive does not extend beyond what is given by those close upon the frontiers, and is only feeble in influence; the assistance which the defensive can derive from this reaches further into the heart of the country, and therefore more of them can be brought into use, and their utility itself differs in the degree of its intensity. A fortress which is made the object of a regular siege, and holds out, is naturally of more considerable weight in the scales of war, than one which by the strength of its works merely forbids the idea of its capture, and therefore neither occupies nor consumes any of the enemy’s forces.

3.—The People.

Although the influence of a single inhabitant of the theatre of war on the course of the war in most cases is not more perceptible than the co-operation of a drop of water in a whole river, still even in cases where there is no such thing as a general rising of the people, the total influence of the inhabitants of a country in war is anything but imperceptible. Every thing goes on easier in our own country, provided it is not opposed by the general feeling of the population. All contributions great and small, are only yielded to the enemy under the compulsion of direct force; that operation must be undertaken by the troops, and cost the employment of many men as well as great exertions. The defensive receives all he wants, if not always voluntarily, as in cases of enthusiastic devotion, still through the long-used channels of submission to the state on the part of the citizens, which has become second nature, and which besides that, is enforced by the terrors of the law with which the army has nothing to do. But the spontaneous co-operation of the people proceeding from true attachment is in all cases most important, as it never fails in all those points where service can be rendered without any sacrifice. We shall only notice one point, which is of the highest importance in war, that is intelligence, not so much special, great and important information through persons employed, as that respecting the innumerable little matters in connection with which the daily service of an army is carried on in uncertainty, and with regard to which a good understanding with the inhabitants gives the defensive a general advantage.

If we ascend from this quite general and never failing beneficial influence, up to special cases in which the populace begins to take part in the war, and then further up to the highest degree, where as in Spain, the war, as regards its leading events is chiefly a war carried on by the people themselves, we may see that we have here virtually a new power rather than a manifestation of increased cooperation on the part of the people, and therefore that—

4.—The National Armament,

or general call to arms, may be considered as a particular means of defence.

5.—Allies.

Finally, we may further reckon allies as the last support of the defensive. Naturally we do not mean ordinary allies, which the assailant may likewise have; we speak of those essentially interested in maintaining the integrity of the country. If for instance we look at the various states composing Europe at the present time, we find (without speaking of a systematically regulated balance of power and interests, as that does not exist, and therefore is often with justice disputed, still, unquestionably) that the great and small states and interests of nations are interwoven with each other in a most diversified and changeable manner, each of these points of intersection forms a binding knot, for in it the direction of the one gives equilibrium to the direction of the other; by all these knots therefore, evidently a more or less compact connection of the whole will be formed, and this general connection must be partially overturned by every change. In this manner the whole relations of all states to each other serve rather to preserve the stability of the whole than to produce changes, that is to say, this tendency to stability exists in general.