So, I was watching a YouTube video (Two Minutes Till Midnight by Aperture) and it in, he said that if two superpowers like the Untied States and Russia ever go to war and use nuclear weapons, that’s it for humans. If they did this, they would both go all out and try to cause as much destruction as possible to each other. So, why are nuclear weapons not banned when they have the capacity to destroy all life on Earth?
Edit: Thanks for the quick responses. I feel I get it a little better now. Have a good day!