Reconsidering Clausewitz on Friction

In the marginalia of his copy of On War, influential fighter pilot-theorist John Boyd laments that Carl von Clausewitz never thought about inducing friction for the adversary: “Overcome friction, yes—but also why not magnify friction for the adversary commanders?” Perusing his pencil marks, “He does not imply that it may be beneficial to increase friction.” If only, Boyd thinks, Clausewitz had “the notion of entropy and the idea of Gödel and Heisenberg and the 2nd Law to generate uncertainty, confusion, disorder as a payoff instead of just interfering with friction as a payoff.” Overall, Boyd finds Clausewitz too inwardly focused, keen “on reducing/overcoming (friction) confusion and disorder,” without seeking to “undermine [the] adversary and diminish his expenditure of effort.”

I imagine Clausewitz rebutting Boyd: If one cannot be certain enough about oneself, or one’s own disposition, then how could one be sure enough of the adversary to affect them in such a way? War takes place in a haze: “three-fourths of those things upon which action in War must be calculated, are hidden more or less in the clouds of great uncertainty.” Following this back-of-the-napkin math, we see that most knowledge of the enemy is uncertain — importantly, just as much of the knowledge about one’s own force and disposition. Moreover, even the degree of uncertainty is uncertain: It is “mehr oder weniger” — more or less. This German phrase is one of the most common phrases that Clausewitz uses, a tick to indicate that he is always hedging his bets.

While Boyd’s critique of Clausewitz points to their epistemic divergence, it also underscores a misunderstanding of the concept of friction. Clausewitzian friction is not an object, but a condition. Friction is a Newtonian concept, which refers to the resistant force between two interacting surfaces. Per Clausewitz, friction concerns how “action in war is movement in a hindering medium.” Out of the originating clash and two-fold fight, the Zweikampf, warfare whips up its own atmosphere that hampers activity therein. It is in this realm of danger, bodily exertion and suffering, uncertainty, and chance that one’s engagement with the world is different, skewed. “Everything is very simple in war, but simplest thing is difficult.” The difference is the hindering difficulty.



To understand how and why, let’s first consider the word “ullage” — one of my favorites. Ullage is the amount by which a bottle or a container comes short of being full. The amount of air trapped in a bottle of wine is that bottle’s ullage. While friction, too, is a kind of lack, it is not the lack itself. Friction is the concept that accounts for the difference between war on paper and war in reality. Ullage, in this case, would be the deviation from the war on paper whereas friction is the underlying condition that makes the difference. It induces the “chasm,” as Clausewitz writes, between planned or anticipated actions and how they unravel under conditions of warfare. Danger, strain and suffering, bias, opinion, and conflicting information, scale, freedom, and multiplicity all impede action. However, these are only indirectly related to the adversary since they arise from the condition of fighting. An adversary may create situations that induce more friction — more uncertainty, more danger, more suffering, more contingency, more distortion between expectations and the encounter with the material world — but friction itself is not something one can unleash. Friction is only ever a concept that depicts the relation between oneself, one’s plans and intentions, and one’s actions. Hamlet, one could say, is a play about friction.

This may explain why Clausewitz’s example of friction proper is not about war but about travel. Whereas Clausewitz considers a traveler trying to “accomplish the two stages at the end of his day’s journey” riding (poor) horses as twilight fades to dark, imagine instead taking a flight, perhaps on Southwest, somewhere. You arrive for your flight, check in, and make it through security only to see that your flight is delayed because the plane took off late from its point of origin. The incoming flight lands but is sent to a different gate. As you are gathering your luggage, you glance up at the monitor and see your flight with “Final Boarding” flashing. Confused, you race to the new gate. The gate agent smiles as your run up, confirming that the flight has not started boarding yet. Instead, it’s delayed again, for maintenance. You cannot find a seat and you need to charge your phone, so you wander away. Over the intercom your flight is announced not for boarding but for cancellation. The delays broke crew day, the duration that limits how long pilots can perform their duties before being obliged to stop. On and on it goes. Any number of personal experiences of flying provide ample experience of friction. Travel, as movement from one point to another, may be simple — but it is also difficult.

Travel can encounter any manner of difficulties, but under the conditions of warfare, these difficulties are amplified. In warfare — and On War — travel is renamed the march. Book five, Military Forces, another book most ignore, focuses on the difficulties of living: marching (movement), bivouacking and billeting (dwelling), maintenance (healthiness), and supplying and providing logistics (nourishing). Ultimately, all actions in war are aimed such that the “soldier is levied, clothed, armed, trained, he sleeps, eats, drinks, and marches, all merely to fight at the right time and place.” The simple acts that prove difficult are not those of fighting, and especially not today given the inherent complexity of the technology involved, but those found in the sheer act of living, which are anything but simple in war given the proximity to death.

It is not just that walking, talking, sleeping, and eating are difficult, but so is thinking, for the bare appearance of the world is skewed. The substance-as-danger distorts the mind through fear, excitement of the passions, and overstimulated sensibilities. Existing is difficult. The substance-as-physical exertion inhibits through the exhaustion of humans (and now machines): There is a limit to use before a rest and refit is required. Endurance is difficult. The substance-as-information refracts because of the process of receiving information or news. As it is processed the information either helps judgment, leading one to critical analysis, or hinders it by leading one to the basest tendencies of human biases. Thinking is difficult. The substance-as-friction-proper amplifies the small things that are unaccountable or unforeseeable in life, like the weather. Acting is difficult.

In an earlier work, Principles of War, Clausewitz also wrestles with friction. This work, which is often considered as falling into the category of prescriptive military theory — it must be remembered it was written directly for the future King of Prussia — ends with a discussion in section four about applying the principles discussed in war. Here the difficulty is not understanding how to fight (an early strike against the necessity of genius), but simply to “remain faithful throughout to the principles.” For the Crown Prince, he deems this point on the difficulty of executing theory in reality as the most important. Again, friction is at the heart. Clausewitz then acknowledges that while “[i]t may be impossible to enumerate exhaustively the causes of the friction,” the main ones are: having confidence in the assessment of the adversary; mitigating the influence of rumor and adjudicating between information streams; trusting subordinates; embracing the suck or, what Frederick II called, “difficulties”; imprecision; overestimating one’s strengths; supply and logistics (considered, too, “the main cause for the unwieldiness of the whole war machine which keeps the results so far beneath the flight of our great plans”); and the distortion of wartime appearances. While situationally more specific, these eight instances of friction do not contradict what is written in On War. Instead, they serve as moments wherein which the danger-exertion-information-friction medium hinders existing, enduring, thinking, and acting in different proportions.



But Clausewitzian friction is not just conceptually tied to the idea of mechanics, warfare also attempts to make itself a machine. In Principles of War, he writes: “The conduct of war resembles the workings of an intricate machine with tremendous friction, so that combinations which are easily planned on paper can be executed only with great effort.” This is related to the underlying critique Simone Weil pens in her essay “The Iliad: Or the Poem of Force,” whereby men are instrumentalized. For her, “force—it is that x that turns anybody who is subjected to it into a thing.” And yet, Clausewitz seems to note, even in the most mechanizing of circumstances, the parts will wear down, the process will sputter and jerk, and the machine will even succumb to “the most insignificant [who] is able to occasion and even some irregularity.” The question is, then: How long can the commander maintain the machine? But also, is there any “kind of oil which is capable of diminishing this friction?

The lubricant is habituation to war and its theoretical twin, methodism. Through a kind of conditioning, which creates structures for the mind and the body, individuals can act as a composite whole in the face of resistance, can act despite the assault on the senses and the prejudices of the intellect. “Habit gives strength to the body in great exertion, to the mind in great danger, to the judgment against first impressions.” Whereas methodism creates “a readiness, precision, and firmness [that] is attained … which diminish the natural friction and make the machine move easier.” And so, unlike Weil who observes how “battles are fought and decided by men deprived of these faculties … who have dropped either to the level of inert matter, which is pure passivity, or to the level of blind force, which is pure momentum,” Clausewitz argues that warfare is never that pure — either of force or of momentum. War is always more or less. The degree to which that is the case is a result of how one has counteracted friction with habit and methodism — in other words, hard, dangerous, yet safe, realistic training.

The logic of force that Weil described correlates to the three Clausewitzian extremes that emerge, independent of Politik, from the clash — to the utmost violence, to make the enemy defenseless, and to maximal strength. The logic of momentum correlates to the puzzlement concerning the standstill, a product of the inherent superiority of the defensive form of warfare. Nor is the defense a form of pure passivity, a contradiction for Clausewitz: The attack entails elements of the defense as force protection and the defense entails elements of the attack as counter-attack. But as all these logics crash into the substantial reality of the world itself, warfare does not attain its extremes. And so Clausewitz must account for two limitations on war and warfare: Politik, the community, the macro, and friction, the individual, the micro. It is here that François Jullien, in his excellent A Treatise on Efficacy, elegantly distills Clausewitz: “The essence of warfare is to betray its model,” and the concept of friction was his attempt to explain why–a way to “theorize that deficiency on the part of theory.” But now this sounds as if we have taken the long way around just to end up back at Boyd and his essay “Destruction and Creation.”

As we return to Boyd, we can see his critique in a new light. If friction, as Jullien quips, is Clausewitz’s attempt to reconcile the fact that warfare will betray its model, then we need a way to update and adjust our model. Boyd argues that with the act of destructive deduction (“unstructuring”) and constructive induction (“restructuring”) we can change our perceptions of reality. This dialectical process of “Structure, Unstructure, Restructure, Unstructure, Restructure is repeated endlessly.” This is hard enough day-to-day, let alone in war. In other words, Boyd identified an added challenge — it’s not just that warfare will betray its model, but that we must adapt and update that model as we go. The full observe, orient, decide, and act (OODA) loop uses feedback to constantly adjusts one’s conceptual settings as one fights. Thus, if we were to rephrase Boyd’s lament in these terms, we see that he wants to create a situation such that there is as much distance as possible between the adversary’s model and the world, but not so much that the adversary realizes the gap and restructures. Clausewitz would now agree, but would still emphasize minimizing one’s own friction — adjusting one’s models according to the difficulties warfare presents — over trying to adjust the adversary’s. In other words, keep it simple, because the simple is hard enough.



Olivia A. Garard served as an active duty officer in the US Marine Corps from 2014 to 2020. She is currently reading the Eastern canon with St. John’s College. Her first book is An Annotated Guide to Tactics: Carl von Clausewitz’s Theory of the Combat. She tweets at @teaandtactics.

Image: 435th Air Expeditionary Wing photo by Daniel Asselta