Friction of war

From On War by Carl von Clausewitz, Book 1, Chapter 7, Friction in War.

As long as we have no personal knowledge of war, we cannot conceive where those difficulties lie of which so much is said, and what that genius, and those extraordinary mental powers required in a general have really to do. All appears so simple, all the requisite branches of knowledge appear so plain, all the combinations so unimportant, that, in comparison with them, the easiest problem in higher mathematics impresses us with a certain scientific dignity. But if we have seen war, all becomes intelligible; and still, after all, it is extremely difficult to describe what it is which brings about this change, to specify this invisible and completely efficient Factor.

Everything is very simple in war, but the simplest thing is difficult. These difficulties accumulate and produce a friction, which no man can imagine exactly who has not seen war. Suppose now a traveller, who, towards evening, expects to accomplish the two stages at the end of his day's journey, four or five leagues, with post horses, on the high road—it is nothing. He arrives now at the last station but one, finds no horses, or very bad ones; then a hilly country, bad roads; it is a dark night, and he is glad when, after a great deal of trouble, he reaches the next station, and finds there some miserable accommodation. So in war, through the influence of an infinity of petty circumstances, which cannot properly be described on paper, things disappoint us, and we fall short of the mark. A powerful iron will overcomes this friction, it crushes the obstacles, but certainly the machine along with them. We shall often meet with this result. Like an obelisk, towards which the principal streets of a place converge, the strong will of a proud spirit, stands prominent and commanding, in the middle of the art of war.

Friction is the only conception which, in a general way, corresponds to that which distinguishes real war from war on paper. The military machine, the army and all belonging to it, is in fact simple; and appears, on this account, easy to manage. But let us reflect that no part of it is in one piece, that it is composed entirely of individuals, each of which keeps up its own friction in all directions. Theoretically all sounds very well; the commander of a battalion is responsible for the execution of the order given; and as the battalion by its discipline is glued together into one piece, and the chief must be a man of acknowledged zeal, the beam turns on an iron pin with little friction. But it is not so in reality, and all that is exaggerated and false in such a conception manifests itself at once in war. The battalion always remains composed of a number of men, of whom, if chance so wills, the most insignificant is able to occasion delay, and even irregularity. The danger which war brings with it, the bodily exertions which it requires, augment this evil so much, that they may be regarded as the greatest causes of it.

This enormous friction, which is not concentrated, as in mechanics, at a few points, is therefore everywhere brought into contact with chance, and thus facts take place upon which it was impossible to calculate, their chief origin being chance, As an instance of one such chance, take the weather. Here, the fog prevents the enemy from being discovered in time, a battery from firing at the right moment, a report from reaching the general; there, the rain prevents a battalion from arriving, another from reaching in right time, because, instead of three, it had to march perhaps eight hours; the cavalry from charging effectively because it is stuck fast in heavy ground.

These are only a few incidents of detail by way of elucidation, that the reader may be able to follow the author, for whole volumes might be written on these difficulties. To avoid this, and still to give a clear conception of the host of small difficulties to be contended with in war, we might go on heaping up illustrations, if we were not afraid of being tiresome. But those who have already comprehended us will permit us to add a few more.

Activity in war is movement in a resistant medium. Just as a man in water is unable to perform with ease and regularity the most natural and simplest movement, that of walking, so in war, with ordinary powers, one cannot keep even the line of mediocrity. This is the reason that the correct theorist is like a swimming master, who teaches on dry land movements which are required in the water, which must appear grotesque and ludicrous to those who forget about the water. This is also why theorists, who have never plunged in themselves, or who cannot deduce any generalities from their experience, are unpractical and even absurd, because they only teach what every one knows—how to walk.

Further, every war is rich in particular facts; while, at the same time, each is an unexplored sea, full of rocks, which the general may have a suspicion of, but which he has never seen with his eye, and round which, moreover, he must steer in the night. If a contrary wind also springs up, that is, if any great accidental event declares itself adverse to him, then the most consummate skill, presence of mind and energy, are required; whilst to those who only look on from a distance, all seems to proceed with the utmost ease. The knowledge of this friction is a chief part of that so often talked of, experience in war, which is required in a good general. Certainly, he is not the best general in whose mind it assumes the greatest dimensions, who is the most overawed by it (this includes that class of over-anxious generals, of whom there are so many amongst the experienced); but a general must be aware of it that he may overcome it, where that is possible; and that he may not expect a degree of precision in results which is impossible on account of this very friction. Besides, it can never be learnt theoretically; and if it could, there would still be wanting that experience of judgment which is called tact, and which is always more necessary in a field full of innumerable small and diversified objects, than in great and decisive cases, when one's own judgment may be aided by consultation with others. Just as the man of the world, through tact of judgment which has become habit, speaks, acts, and moves only as suits the occasion, so the officer, experienced in war, will always, in great and small matters, at every pulsation of war as we may say, decide and determine suitably to the occasion. Through this experience and practice, the idea comes to his mind of itself, that so and so will not suit. And thus he will not easily place himself in a position by which he is compromised, which, if it often occurs in war, shakes all the foundations of confidence, and becomes extremely dangerous.

It is, therefore, this friction, or what is so termed here, which makes that which appears easy in war difficult in reality. As we proceed, we shall often meet with this subject again, and it will hereafter become plain that, besides experience and a strong will, there are still many other rare qualities of the mind required to make a man a consummate general.

War is an exercise of will among multiple loosely coupled systems (weather, topography, supplies, logistics, etc.) highly contingent, evolving, and with hidden feedback mechanisms and non-linear effects.  The array of knowledge and experience required of a general is vast and the pace frantic.  The knowledge problem is rife, summed up as the fog of war.  Most issues must be responded to immediately with fractional knowledge.  The role of first principles and useful heuristics are outsized.  

And it all comes down to constant risk and odds calculations in real time with loss of life and attainment of imposed goals as the stakes.  

Or, as Clausewitz says, friction.