MAD & Nuclear Deterrence

Peace by mutually assured suicide — the strangest equilibrium in the history of states.

The brief

By the mid-1960s, both the United States and the Soviet Union had built nuclear arsenals able to inflict society-destroying damage even after absorbing a first strike. The strategic condition that emerged from this fact — Mutually Assured Destruction, with the unimprovable acronym MAD — held that nuclear war between the superpowers was unwinnable, and that the only stable equilibrium was for both sides to know with certainty that any first strike would result in their own annihilation. At the Pentagon Robert McNamara made assured destruction — the capacity to inflict unacceptable damage after taking a first strike — a central planning criterion; the broader acronym came from a critic, the Hudson Institute's Donald Brennan, who chose it so it would spell the English word.

The doctrine has the structure of a paradox: peace is preserved by credibly threatening apocalypse. Stability requires that retaliatory forces be invulnerable to a first strike — hence the nuclear triad: submarine-launched missiles hidden in the oceans, road- or silo-based land missiles, and bombers once kept on permanent airborne alert. It also requires that defense itself be renounced, the logic behind the 1972 ABM Treaty: a shield that worked would let one side strike first without fear of reprisal, breaking the symmetry that kept the peace. And it requires that the other side believe you would actually use them, which means cultivating a kind of strategic insanity at the highest level — Nixon even courted it deliberately, his 'madman theory' — and automating retaliation enough that no decapitating strike could silence it, as the Soviets did with their semi-automatic Perimeter system. The Cold War was, against all expectation, the longest stretch without war between great powers in modern European history. Whether this was because of MAD or despite MAD is among the most important unresolved arguments in political science. The optimistic reading is that nuclear weapons made great-power war irrational and obsolete. The pessimistic reading — pressed by close calls like 1962, the 1983 Able Archer scare, when Soviet intelligence and some forces reacted as if the NATO exercise might conceal preparations for attack, and false alarms like the one Stanislav Petrov reported but correctly judged spurious in 1983 — is that we were lucky for forty-five years, and luck is not a strategy.

Why nowNine states have nuclear weapons as of 2026; several more could in principle cross the threshold, but the distance from technical capacity to a weapon ranges from months to many years. Russia rattling its arsenal over Ukraine, North Korea under no constraint, an Iran whose programme has been bombed but not resolved, an India and Pakistan that already treat them as coercive tools — the assumptions of MAD do not generalize cleanly to a multipolar nuclear world, where deterrence must hold across many asymmetric, mutually distrustful pairs at once. This may be the most consequential under-priced risk on the planet.