1) During the Cold War, the US and USSR came dangerously close to nuclear war on several occasions due to miscommunications and technical errors that were narrowly avoided. 2) In 1983, Soviet satellites detected a US missile launch, wrongly thinking it signaled an impending attack, bringing the world closer to nuclear war than ever before. 3) Other close calls include a computer error that told US forces they needed to launch a nuclear attack and issues with nuclear weapons authorization protocols that could have led to accidental launches.