Just as coup d’oeil links strategy to imagination, so Clausewitz’s concept of friction ties theory to experience. These “must never disdain or exclude each other,” he writes: “[O]n the contrary, they support each other.”45 That places uncertainty within a universal framework. Or, to put it another way, Clausewitz anticipates, by more than a century, Murphy’s Law: that what can go wrong will. Or, still more succinctly, shit happens.46
