It’s for this reason that people (Bohr for example) who made the atomic bomb saw a ray of hope - it made large scale war too expensive to even try given that your enemy would nuke you back.
That is unless we all sign paperwork saying we won't use these big huge wastes of GDP we've stockpiled like someone with a hoarding complex, and resume war as usual.
You don't even need the paper. Just the political will on both sides. That is what mutually assured destruction is about: I don't trust them to not use theirs, but I can assure they don't win if they do.
It has been hotly debated on if mutually assured destruction is actually why we haven't got into a nuclear war or not. You can take either side of the debate with no way to know for sure who is right.
