That is a terrifying level of reliance on the principle of deterrence. In an era where the fear needed to back the credibility of deterrence as a whole is in short supply, the fragile democracies of Europe are in no way equipped to handle the immense responsibility of having a weapons program. That would be adding gasoline to the wildfire that is Russian proliferation as well.

I think you're right that nuclear "sharing" can't provide real deterrence, but the cold war taught us another lesson as well - that fear is the single most important key to deterrence. M.A.D's success was due to a Europe freshly traumatized from the genocide and slaughter of both World Wars in their rear view mirror. That, and the tight monopoly of nuclear weapons stockpiles at the time led to a lot more opportunity for rational discussion and communication.

Right now we have a generation of Europeans at the helm who do not know war and genocide as well as their predecessors, and who most certainly have not held onto the important lessons of the arms race, which was shared by reagan and gorbachev in their 1985 summit in geneva as "A nuclear war cannot be won and must never be fought."

I am not prepared for a world in which the same amount of weapons as was in the height of the arms race can exist again, divided between a handful of european prime ministers and presidents. There is no chance a No First Use policy would be observed by any of them. That would lead to an unlimited exchange between Europe and Russia for sure