I think MAD between a small number of (mostly rational) actors was the best case scenario. Sure, nuclear states vs. non-nuclear traditional states is the most

I think MAD between a small number of (mostly rational) actors was the best case scenario. Sure, nuclear states vs. non-nuclear traditional states is the most likely use right now, but we're not that far off from non-state actors being able to make nuclear weapons. Right now the only real protection is limiting access to fissile material.