In the opening days of the October War of 1973, Egyptian infantry crossed the Suez Canal carrying a weapon Israeli tank doctrine had no answer to: the Sagger, a wire-guided anti-tank missile that a single soldier, kneeling in the sand, could steer into a tank two kilometres away. The first engagements were a slaughter. The reports from Sinai read like the end of the armoured force.

Then something faster than any procurement cycle happened. Within three to six days, tank officers at the front had improvised a counter-drill: watch for the launch signature, throw the operator off his aim with fire and dust, keep moving while the missile flies. It was crude and expensive in shells and nerves — and it worked well enough that, as one veteran put it, ambush was soon all the Egyptian teams had left.

The most interesting sentence, though, comes from after the war. Meir Finkel — an Israeli brigadier general of armour who turned the 1973 shock into a theory of military recovery in his book On Flexibility — reports what the post-war analysis found: the celebrated missile had been “the least of the factors” behind Israel’s tank losses. The cognitive shock had done more damage than the warhead. Crews died in the days of not knowing, not because the weapon was unanswerable.

That finding reverses the standard planning question. Militaries spend fortunes trying to guess which weapon will surprise them next — and the record says they will guess wrong. Finkel’s conclusion points the budget elsewhere: the scarce resource is not foresight, it is recovery time. Build the force that gets over its shock in days, not seasons. What must be true on the morning after the surprise matters more than every prediction made the morning before.