Two Superpowers and the Arms Race

After 1945, Europe split into two armed camps. NATO, led by the United States, tied together Western Europe and North America; the Warsaw Pact, led by the Soviet Union, bound Eastern Europe behind it. Troops and tanks massed along the line running through the middle of Germany, each side ready to fight a conventional war that both feared would go nuclear. But the real contest was in warhead counts, not tank columns. Starting from a handful of bombs in 1945, both superpowers built arsenals that climbed into the tens of thousands by the mid-1980s, each new weapon justified as a response to the other side's buildup.

This is where mutually assured destruction, or MAD, comes in. The logic is backwards from ordinary safety: you stay safe not by protecting yourself but by making sure you cannot protect yourself. If both sides have enough warheads, and enough ways to launch them even after absorbing an attack, then neither can strike first without guaranteeing its own destruction. That is why both superpowers avoided building real missile defenses. A working shield would let one side imagine it could strike first and survive the reply, which would collapse the whole deterrent logic that was keeping the peace.

Intercontinental ballistic missiles changed the stakes further. Once missiles could cross an ocean in under thirty minutes, there was no time to confer, double check, or call off a mistaken alarm. Decisions that once took hours now took minutes, which made arms control talks and hotlines between Washington and Moscow matter just as much as the weapons themselves, and set up the detente and treaty efforts covered next.