Ben, I write about the chances of Putin nuking Ukraine at length in Killer In The Kremlin.
Putin won't use a nuke. Because...
1) The Chinese will kill him if he does. A nuke would cause a global recession and the Chinese need a rich West to buy their stuff. Xi has said: "no nuclear adventurism."
2) Russia is next door to Ukraine. The wind blows west to east. If he nukes Ukraine, he irradiates western and southern European Russia.
3) The Russian machinery, aware of 1) and 2) above will stop him.
So your dark pessimism is not founded in facts.
You are Kremlin whispering.
I learnt Russian at school; was taught Russian politics at LSE by a professor who had lived through both Russian revolutions of 1917; befriended four members of the Russian opposition - poisoned, then shot; shot; shot; poisoned, survived, poisoned, died; met and challenged Putin to his face in a mammoth museum in Siberia in 2014.
Please set out your expertise in Kremlinology here.
If you can't, read Killer In The Kremlin.
And learn to think.
He goes nuclear, everybody goes nuclear and it's the end of everything