This fear of nuclear warfare was heightened during which of the following events

The Cuban missile crisis

Explanation:

The Cuban Missile Crisis was a time of heightened confrontation between the Soviet Union, the United States, and Cuba during the Cold War.

It may have been the moment when the Cold War came closest to a nuclear war. There was a coup in Cuba in 1959. A small group led by Fidel Castro took power in this Cuban Revolution.

The Cuban Missile Crisis comes to an end. The Cuban Missile crisis comes to a close as Soviet leader Nikita Khrushchev agrees to remove Russian missiles from Cuba in exchange for a promise from the United States to respect Cuba's territorial sovereignty.