That is a problem, I'm afraid if the peace don't come quick Russia can use it's nuclear arsenal.
And I think it can be used now since Russia already claim some territory to them.
Putin can do it without any reason just fine. What you seem to be saying is that either you think his little annexation spree gives him sufficient reason, or at least that you think it gives him sufficient reason inside Russia...
It is an insane proposition, but Putin is making it precisely in the hope everyone might reason like you – and let him get away with lopping off bits of Ukraine that are 1) not Russian, 2) not under Russian control properly even – but everyone should just immediately stop doing what they are doing, and let him get away with what he has been doing. Or else – nukes – QED. Everyone should be intimidated into passivity.
But should he fire something like that off (unless he goes for a massive decapitating First Strike against the US, effectively making the US disappear in one go, not that it is really possible) then the so far proposed insanity of "tactical" nukes against Ukraine will get a US/NATO conventional response destroying all Russian military assets in Ukraine and the Black Sea. So then Putin WILL lose all of Ukraine.
What he can do then is of course to again escalate the nuclear strikes, targeting western Europe/the US, which will result in nuclear retaliation, etc... But it will only happen in the steps of – 1) Russia uses nuclear weapons against Ukraine, gets hit by a conventional response and – 2) Russia escalates by a second barrage of nuclear weapons more generally against everyone it decides it is aggrieved by – and only then as nr 3) is Russia met by nuclear retaliation, when it has already reduced much of the western world to nuclear rubble.
That is the worst case scenario Putin really want us all to think that he might really carry out...
The US, NATO etc. will under no circumstances initiate a nuclear exchange. Russia is threatening to do so. And by implication, if if gets the now promised
conventional response to a Russian first-use of nuclear weapons, it really only can escalate by keeping attacking with nuclear weapons.
How crazy should we gauge Russia at this point? How real are these Russian threats really? Should the Russian threats just stop everyone cold in their tracks, and allow Putin to make off with these Ukranian lands he has barely seized (if one is generous), and is fast losing?