Final answer:
Mutually Assured Destruction (MAD) is a Cold War theory in which both the United States and the Soviet Union believed that neither side would start a nuclear war.
Step-by-step explanation:
Mutually Assured Destruction (MAD) is a Cold War theory in which both the United States and the Soviet Union believed that the use of nuclear weapons by one side would result in the complete annihilation of both sides. It was based on the assumption that, due to the destructive power of nuclear weapons, neither side would initiate a nuclear war out of fear of their own destruction. This was seen as a deterrent to prevent a nuclear conflict from breaking out.
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