I'm broadly sympathetic to the argument that the multipolar world we're in now makes a good case for nuclear weapons adoption. But Germany probably isn't the one Europe wants to arm itself. And even if it did, their Greens wouldn't allow it.
Giving up the nukes allowed Ukraine to attract foreign aid and build an economy for 20 years before invasions began. Who knows what would have happened if they kept nukes and didn't get necessary aid and couldn't build their economy or maintain the weapons.
So does Montana. That doesn’t give Helena any sovereignty points.
Build nukes and plenty gigantic bunkers for the population, nothing else. And then follow the doctrine of immediate nuclear escalation upon any territorial infraction. Plane got off course in bad weather? Grab your Sauerkraut and bye bye Moscow.
All sorts of questions to ask. Yes, if our timeline was otherwise unchanged, but the nukes were kept and maintained, it seems unlikely that invasion in 2014 would have happened... But it's a big change to the timeline to keep the weapons, and there's too many unknowns to predict the resulting changes. I do strongly suspect few countries will accept similar assurances in the future, unless under duress, but then Ukraine wasn't exactly free from duress at the time either.
Given how insistent the international community was on making sure those nukes were disposed of, and how economically devastated post Soviet countries were, I don’t think Ukraine stood any chance of having a nuclear deterrent.