The Cuban Missile Crisis

The world was at the edge of a third world war. This was the result of a variety of things: the Cuban Revolution, the failure of the Bay of Pigs invasion, US anti-communism, insecurity of the Soviet Union, and Cuba's fear of invasion all made causes for war. However, war was not the result due to great cooperation from both President Kennedy and President Khrushchev and each of the decisions made by the leaders was …

…not have been willing to defend Cuba from American invasion anyway, suppose a war did break out. Many things could have changed the course of the crisis to the point of disaster: if Kennedy had chosen to use air strikes, if Russia had crossed the quarantine line, if Kchruschev didn't agree to peace, if the missile bases had been finished. Luckily these things weren't, and the world was saved from a potentially catastrophic nuclear war.