The use of Nuclear Weapons are constantly related to practically irreversible consequences and the use of them must take it in consideration. Once the narrative is to help, the use of the "Asymmetric Advantage" is also one that is to be marked in History for causing horrible consequences to future generations.
Also, the use of weapons of mass destruction can escalate a war and invite other powers who might have the same weapons to escalate the whole situation. Russia/USSR being a communist country, could have tried to do something about the US's use of an atomic bomb since North Korea and Vietnam were under communist governments.
One incident would definitely be during the cold war more specifically during The Bay Of Pigs another would be during a false alarm in which we thought Russia had fired nuclear weapons at us and refrained from firing back before being sure
