Definition of mutual assured destruction in English English dictionary
The threat of massive retaliation using nuclear weapons should a potential enemy use them first, both sides being annihilated in the event of war
Severe, unavoidable reciprocal damage that superpowers are likely to inflict on each other or their allies in a nuclear war, conceived as the heart of a doctrine of nuclear deterrence
constant threat that was present between the USA and the Soviet Union and which helped prevent nuclear war (both countries had the ability to completely annihilate the other), MAD