Either all nuclear weapons should be eliminated (unrealistic), or more countries should have them. The current system is a handful of countries imposing and maintaining an unfair advantage over everybody else.
the issue with proliferation is that it increases the risks of nuclear materials and knowledge falling into the hands of really dodgy non-state actors in the event of state collapse/incompetence. Like, even total rogue states like DPRK and Iran are "rational" enough of their weaponry that they would understand the risks of using them unilaterally; logic that may not apply to terrorist groups that could spring up during a civil war.
Correct, and in the dense and flammable cities of the developing world, even a small number of nuclear detonations would be enough to cause a global catastrophe.
On the other hand, it's not clear to me that the other option given (total non-proliferation) is actually preferable, as I would argue the existence of nuclear weapons is the primary reason for the lack of great power wars since 1945 - and for the record, $73 billion is an extremely low price to pay for something which is doing >90% of the global defense industry's job in maintaining global peace.
The ideal scenario in my view, which I think is actually achievable in the long run, is to bring the great powers down into the mid double-digit warhead range - enough to remain an insurmountable deterrent, but insufficient in the case of an accidental exchange to threaten human extinction, as do current stockpiles.
