On War

by Carl von Clausewitz

It is only in small, compactly shaped states that it is possible to have such a unity of military force, and that probably all depends upon a victory over that force. Such a unity is practically impossible when larger tracts of country, having for a great extent boundaries conterminious with our own, are concerned, or in the case of an alliance of several surrounding states against us. In such cases, divisions of force must necessarily take place, giving occasion to different theatres of war.

The effect of a victory will naturally depend on its greatness, and that on the mass of the conquered troops. Therefore the blow which, if successful, will produce the greatest effect, must be made against that part of the country where the greatest number of the enemy’s forces are collected together; and the greater the mass of our own forces which we use for this blow, so much the surer shall we be of this success. This natural sequence of ideas leads us to an illustration by which we shall see this truth more clearly; it is the nature and effect of the centre of gravity in mechanics.

As the centre of gravity is always situated where the greatest mass of matter is collected, and as a shock against the centre of gravity of a body always produces the greatest effect, and further, as the most effective blow is struck with the centre of gravity of the power used, so it is also in war. The armed forces of every belligerent, whether of a single state or of an alliance of states, have a certain unity, and in that way, connection; but where connection is there come in analogies of the centre of gravity. There are, therefore, in these armed forces certain centres of gravity, the movement and direction of which decide upon other points, and these centres of gravity are situated where the greatest bodies of troops are assembled. But just as, in the world of inert matter, the action against the centre of gravity has its measure and limits in the connection of the parts, so it is in war, and here as well as there the force exerted may easily be greater than the resistance requires, and then there is a blow in the air, a waste of force.

What a difference there is between the solidity of an army under one standard, led into battle under the personal command of one general, and that of an allied army extended over 50 or 100 miles, or it may be even based upon quite different sides (of the theatre of war). There we see coherence in the strongest degree, unity most complete; here unity in a very remote degree often only existing in the political view held in common, and in that also in a miserable and insufficient degree, the cohesion of parts mostly very weak, often quite an illusion.

Therefore, if on the one hand, the violence with which we wish to strike the blow prescribes the greatest concentration of force, so in like manner, on the other hand, we have to fear every undue excess as a real evil, because it entails a waste of power, and that in turn a deficiency of power at other points.

To distinguish these “centra gravitatis” in the enemy’s military power, to discern their spheres of action is, therefore, a supreme act of strategic judgment. We must constantly ask ourselves, what effect the advance or retreat of part of the forces on either side will produce on the rest.

We do not by this lay claim in any way to the discovery of a new method, we have only sought to explain the foundation of the method of all generals, in every age, in a manner which may place its connection with the nature of things in a clearer light.

How this conception of the centre of gravity of the enemy’s force affects the whole plan of the war, we shall consider in the last book, for that is the proper place for the subject, and we have only borrowed it from there to avoid leaving any break in the sequence of ideas. By the introduction of this view we have seen the motives which occasion a partition of forces in general. These consist fundamentally of two interests which are in opposition to each other; the one, the possession of territory strives to divide the forces; the other, the effort of force against the centre of gravity of the enemy’s military power, combines them again up to a certain point.

Thus it is that theatres of war or particular army regions originate. These are those boundaries of the area of the country and of the forces thereon distributed, within which every decision given by the principal force of such a region extends itself directly over the whole, and carries on the whole with it in its own direction. We say directly, because a decision on one theatre of war must naturally have also an influence more or less over those adjoining it.

Although it lies quite in the nature of the thing, we must again remind our readers expressly that here as well as everywhere else our definitions are only directed at the centres of certain speculative regions, the limits of which we neither desire to, nor can we, define by sharp lines.