It may be:
It was a nuclear bomb. Everyone was afraid of a nuclear bomb. The nuclear power plant malfunctioned. The Cold War was about fear of nuclear attack.
nuclear warfare
a nuclear war
fear
Fear of Nuclear War Fight against Communism / Spread of Communism
An end result of nuclear war.
luck, fear, etc.
War fear that the Nazis would do it first - then there would be no chance to stop them.
Because the USSR had nuclear bombs that they were threatening to use on the Americans.
The fear of nuclear war, often referred to as nuclear anxiety or nuclear dread, stems from the catastrophic consequences that such a conflict could entail, including massive loss of life, long-term environmental damage, and societal collapse. This fear is amplified by historical events, such as the bombings of Hiroshima and Nagasaki, and ongoing geopolitical tensions between nuclear-armed nations. It also reflects broader anxieties about humanity's ability to manage powerful technologies and the potential for human error or miscalculation in conflict situations. Ultimately, the fear represents a deep concern about the fragility of global security and the moral implications of nuclear weapons.
now do you mean after the cold war or during. if during it was from all the fear of nuclear attack
a fear that they both would be destroyed in nuclear war. That is called Mutually Assured Destruction (MAD)