The Main Thing
We could all use a little Clausewitz lesson.


Mackubin Thomas Owens

I am often asked why the nation’s war colleges and command and staff schools spend so much time reading a book by Carl von Clausewitz, a Prussian officer who died over a century and a half ago. How, they wonder, can someone who wrote so long ago have anything of value to say to modern soldiers on a high-tech battlefield?

Events of the last week in Iraq provide the answer. Clausewitz developed a theory of war, the elements of which appear to be universal and timeless. A good theory is descriptive, predictive, and prescriptive: It should adequately describe the various phenomena associated with its subject matter; permit individuals to predict what will happen in the future by extrapolating from the present; and offer a guide for action. This is what Clausewitz does.

Clausewitz’s descriptions of war have never been equaled. He wrote that war is a “remarkable trinity” composed of first, “primordial violence, hatred, and enmity” (the realm of the people); second, “chance and probability within which the creative spirit is free to roam” (the realm of the commander and his army); and third, the “element of subordination, as an instrument of policy, which makes [war] subordinate to reason alone” (the realm of the government).

While the character of war is infinitely variable, the nature of war is basically immutable. It is a violent clash between opposing wills, each seeking to prevail over the other. In Clausewitz’s formulation, our will is directed at an animate object that reacts, often in unanticipated ways. This cyclical interaction between opposing wills occurs in a realm of chance and chaos.

Since war is a human enterprise, the human dimension is central to the proper understanding of the phenomenon. Accordingly, war involves intangibles that cannot be quantified. War is shaped by human nature, the complexities of human behavior, and the limitations of human mental and physical capabilities. Any view of war that ignores what Clausewitz called the “moral factors,” e.g. fear, the impact of danger, and physical exhaustion, is fraught with peril. As the Prussian observed, “Military activity is never directed against material forces alone; it is always aimed simultaneously at the moral forces which give it life, and the two cannot be separated.”

Clausewitz was reacting against a belief that took hold during the latter part of the 18th century: the idea that war could be quantified and thereby rendered predictable in a mathematical sense. Advocates of such a view included Henry H.E. Lloyd (1720-1783) and Dietrich Adam Heinrich Von Bulow (1757-1807), who, according to Sir Michael Howard, sought to find a set of “rational principles based on hard, quantifiable data that might reduce the conduct of war to a branch of the natural sciences…from which the play of chance and uncertainty” could be entirely eliminated.

Clausewitz dismissed such attempts to reduce the conduct of war to quantitative principles as “completely useless” fantasies. He wrote of Von Bulow and Lloyd that they tried

to equip the conduct of war with principles, rules, or even systems. This did present a positive goal, but people failed to take adequate account of the endless complexities involved. As we have seen, the conduct of war branches out in almost all directions and has no definite limits; while any system, any model, has a finite nature of a synthesis. An irreconcilable conflict exists between this type of theory and actual practice….[These attempts] aim at fixed values; but in war everything is uncertain, and calculations have to be made with variable quantities. They direct the inquiry exclusively toward physical quantities, whereas all military action is entwined with psychological forces and effects. They consider only unilateral action, whereas war consists of a continuous interaction of opposites.

Retired Marine Lieutenant General Paul Van Riper once suggested that a good metaphor for war is white-water canoeing. As one seeks to navigate the treacherous current, the water surges, crashes, eddies, and flows in unpredictable ways. The nature of the white-water canoeing places a premium on the ability to react properly to the fluid environment. One lapse and the boat crashes into the rocks or capsizes.

In an important respect, of course, this metaphor understates the problem. While the rapids of a river may seem like they have a will of their own, a river is still an inanimate object. But as Clausewitz notes, “The art of war deals with living and with moral forces. Consequently, it cannot attain the absolute, or certainty; it must always leave a margin for uncertainty, in the greatest of things as much as in the smallest.”

The behavior of the Iraqis over the past few days confirms Clausewitz’s observation that “war is not the action of a living body on a lifeless mass… but always the collision of two living forces.” The idea of a campaign of “shock and awe” is an example of what has been called “effects based operations” (EBO). The idea behind EBO is that the effects of a well-targeted but overwhelming attack would extend beyond the targets themselves, leading to confusion and paralysis. Shock and awe was based on the assumption that an overwhelming attack of political targets would cause the Iraqi regimes to crack early in the war.

But as my good friend, retired Army Colonel Bob Killebrew, said the other night on MSNBC, one should never create a plan that depends for its success on the enemy’s cooperation. As it turns out, for whatever reason, the Iraqi resistance has been more robust than in 1991. Much of it has to do with the fear created by Saddam’s Gestapo, the Fedayeen Saddam and other irregular troops whose job has been to terrorize both Iraqi soldiers and civilians into fighting against the coalition.

The interdependent nature of war leads to the sort of unpredictability we have seen in the Iraq war. As Clausewitz observed, military action does not produce a single reaction but a dynamic interaction, the very nature of which is bound to lead to unpredictability. The inherent unpredictability of war is magnified by three other phenomena that Clausewitz addresses in some detail: chance, uncertainty, and friction, all of which have been apparent in the fighting in Iraq.

War takes place in the realm of chance and uncertainty, constrained by time, and always subject to friction. As Clausewitz observed, “No other human activity is so continuously and universally bound up with chance” as is war, and “Three-quarters of the factors on which action in war is based are wrapped in a fog of greater or lesser uncertainty.”

Like uncertainty, friction in war also seems to be an intractable problem. Clausewitz identifies friction as “the only concept that more or less corresponds to the factors that distinguish real war from war on paper.” He continues:

everything in war is simple, but the simplest thing is difficult. The difficulties accumulate and end by producing a kind of friction that is inconceivable unless one has experienced war. Countless minor incidents — the kind you can never really foresee — combine to lower the general level of performance, so that one always falls far short of the intended goal….The military machine — the army and everything related to it — is basically very simple and therefore seems easy to manage. But we should keep in mind that none of its components is of one piece: each part is composed of individuals,…the least important of whom may chance to delay things or somehow make them go wrong….This tremendous friction, which cannot, as in mechanics, be reduce to a few points, is everywhere in contact with chance, and brings about effects that cannot be measured, just because they are largely due to chance.

Clearly, small causes can be amplified in war until they produce unanticipated macro-effects. This is what has happened in Iraq.

So where do we go from here? Despite the fact that shock and awe has not yet yielded results, at least as far as we can tell, it could be just a matter of a delayed outcome. In Afghanistan, planners spoke of “tipping,” a point at which resistance began to crumble and the enemy was routed. This could still happen in Iraq.

Meanwhile, U.S. planners are adapting to the new Iraqi tactics. It was Helmuth von Moltke, chief of the Prussian General Staff during the wars of German unification, who observed that “…no plan of operation extends with any certainty beyond the first contact with the main hostile force. Only the layman thinks that he can see in the course of the campaign the consequent execution of the original idea with all the details thought out in advance and adhered to until the very end.”

His observations apply to the current situation in Iraq. The commander, wrote Molthke in a riff on Clausewitz, must keep his objective in mind, “undisturbed by the vicissitudes of events.”


The adversary, as Clausewitz reminds us, possesses an active will that responds and adapts to our actions. We can be assured that planners are hard at work, not changing “the main thing,” but adapting to the reactions of an enemy that has failed to cooperate with our war plan. And that’s why officers still study Clausewitz.

— Mackubin Thomas Owens, an NRO contributing editor, is on leave from the Naval War College in Newport, R.I., to write a history of U.S. civil-military relations.