That's the obsoleted narrative that the proliferation of nuclear weapons would create long-lasting world-wide peace.
Easily disproven by current events.
> assuming rational actors, which Putin is not
Hence the criticism: https://en.wikipedia.org/wiki/Mutual_assured_destruction#Cri...
Unsurprising the Doomsday Clock is showing increased threat level.
It's clearly not obsolete nor disproven by current events at all.
The conflict would have to involve two nuclear powers at war with eachother. The US and Russia are not at war; NATO and Russia are not at war; MAD hasn't failed what-so-ever, nor has it even come to that context. The situation is presently one nuclear power vs a non-nuclear power (being supplied with weapons by foreign allies).
The present events don't disprove the effectiveness of MAD any more than Russia in Afghanistan did.
Not necessarily, after a certain point MAD comes to play ( assuming rational actors, which Putin is not).