Personally: let everybody who needs one have a few instead of relying off the caprices of others. It's not like a small country wouldn't still be having a death sentence if they chose to nuke a big one. But it provides psychological security, as well as deep mutual interest to never let any crazy network have access to a bomb through mutual complicity.
I don't think this is the solution.
We have a huge number of people willing to press a button and cause pain. And it's escalating. I don't want more of those.
Instead, we should isolate countries that tend to be the aggressors. The Iranians, the Israelis, the Americans, the Russians. Because we have long pretended to not see or found excuses for those aggressions.
Needless to say, we also need to get rid of systems that concentrate too much executive power in a single person. Authoritarian governments are the first, but presidential and semi presidential republics come second.