Clausewitz called it *Nebel des Krieges* — the fog of war. Everything in war operates under uncertainty: where is the enemy, what are their intentions, what do they know about you.

The crucial insight: the fog is irreducible. You cannot wait for certainty because certainty never arrives. The competent commander acts on incomplete information while continuously updating as new information comes in.

This is [[@dave/bayes-as-updating]] applied to violence. Prior + evidence → posterior. The prior is your intelligence estimate. The evidence is what your scouts report. The posterior is your updated picture of the battlefield.