The US also tried to slow the spread of communism by founding NATO and with CIA interventions in elections where communists had a chance, as in Italy. But despite all the great spy novels and shaken, not stirred martinis, the Cold War never did heat up in Europe. Probably the most important part of the Cold War that people just don't remember these days is the nuclear arms race. Both sides developed nuclear arsenals, the Soviets initially with the help of spies who stole American secrets. Eventually, the nuclear arsenals were so big that the US and USSR agreed on a strategy appropriately called MAD, which stood for Mutually Assured Destruction. Thanks, Thought Bubble. And yes, nuclear weapons were and are capable of destroying humanity many times over.