I’m very glad that nothing important depends on my opinion on this and I can freely theoretize and rant, but I doubt Putin would use nukes so easily. At his core he’s still a coward, and he has to know that the ‘West’ couldn’t afford to not react to Russia nuking a European country.
Having said that, even if the threat of Russia using nukes were very real, it shouldn’t weaken our resolve to support Ukraine and put a stop to Russia’s aggression. Because no matter the circumstances, people like Putin cannot be allowed to have any way of forcing the world to stand back and let them commit crimes at will.
Throughout history, appeasement has never worked in anybody’s favour except the aggressor’s. If it turns out that a nuclear retaliatory strike in response to a Russian nuclear attack on another country really is what it takes to stop Putin, then so be it. It can’t be worse in the long term than letting him just take whatever he wants. In that case I just wish we could get this over with already.
Putin has effectively vowed (and for the better part of three years also attempted) to slaughter them anyway. To them the threat of nukes just translates to “if you don’t stop fighting back while I try to kill you, I will try to kill you even harder!” That certainly wouldn’t stop me, that’s for sure.