I think the analogy is a little off, because any particular person with a gun might be expected to be irrational, psychotic, etc. However, MAD is based on the principle that states are rational actors, and that no rational actor would ever risk a sizable portion of their own population, economy, etc, for literally no gain other than like destruction in the adversary's country. No matter how terrible any given leader is (and the USSR had a few that were certainly that), the decision to use nukes would almost certainly be by committee, even if the choice to fire ultimately lay with one person.Does everyone owning and carrying a gun make us all safer on a personal level, any more than every sovereign nation having a nuclear arsenal make global politics safer?