The Cuban Missile Crisis. The fear on both sides was that someone would push a button and all out war (perhaps the end of the planet as we understand it) would result. Both countries had ICBMs but America's were better. They could hit Russia. Russia had no real answer and Cuba is too small a defensive position. So Khrushchev blinked and took his threat home. It didn't take her long to catch up but by that time the political situation altered.
