After the Second World War, the nuclear willy-waving contest known as the arms race took off in earnest, with Nato and the Warsaw Pact countries stocking up on atomic bombs like they were going out of fashion.
In the early 1960s, the USA was “winning”. At the start of the decade, it boasted nearly 20,000 warheads. And it was positioning them all around the Eastern bloc, making the Soviets very nervous.
The Soviet Union was on the back foot. It only had a couple of thousand warheads. Sure, that was enough to destroy civilisation as we know it. But it wasn’t enough for a self-respecting world leader to feel safe in his own trousers.
So, the USSR decided to build some missile silos in Cuba and quietly stuff a few megatons there without Uncle Sam noticing. But Uncle Sam did notice.
Pictures from a U2 spy plane showed Russian soldiers setting up nuclear missiles. President Kennedy convened his top advisers and they discussed what to do. The hawks favoured bombing Cuba; the doves thought that was probably a bad idea.
They decided to issue an ultimatum.
So, on 22 October 1962, Kennedy went on national TV and announced a blockade of Cuba, demanding that the Soviets remove their weaponry from America’s backyard, or there would be trouble.
The world held its breath. There was a real sense that the West and the East were on the brink of a nuclear war. Would the Soviets back down? And how would the US react if they didn’t?
Two days later, Khrushchev replied. The US blockade was an “act of aggression” and Soviet ships would continue to go to Cuba.
The world started going blue in the face. But after much diplomatic to-ing and fro-ing, and to the world’s relief, an agreement was reached.
The USSR would withdraw its missiles as long as the USA promised not to invade its Caribbean ally. Secretly, the USA also agreed to remove its own missiles from Turkey, alarmingly close to the Soviet Union’s borders. Armageddon had been averted.