"APPEASEMENT WON'T WORK" they say as they're vaporized into radioactive dust
Russia is not going to nuke us bro because Russian wants to win, and the thing with nuclear war is, everyone loses. That's the whole point of nuclear deterrence. I don't think Putin is mad enough to think the total annihilation of Russia is worth it to stick it to the Americans, and even if he were, the chain of people involved in actually launching the nukes is deliberately long enough to ensure one man's madness can't destroy the world. It's like that for the US, for the UK, for France, and for Russia.
Aside from that, Russia has a very clear nuclear doctrine that outlines the circumstances where they would actually use nuclear weapons. Quote:
"Russia reserves the right to use nuclear weapons in response to the use of nuclear and other types of weapons of mass destruction against it or its allies, and also in case of aggression against Russia with the use of conventional weapons when the very existence of the state is threatened."
While they do allow for the use of tactical nukes on the battlefield, when it comes to strategic nukes, we are nowhere near the conditions that would necessitate their use. Indeed there could be a shooting war between Russia and NATO in Ukraine and that would not trigger a nuclear exchange. If NATO forces are charging towards Moscow or dropping anthrax on Russian cities, different story.
And it's true appeasement won't work. If Ukraine agreed to surrender, formally cede all the annexed territory and demilitarise itself, guess what will happen? Russia will dig into its new territory, replenish and expand its forces, and in a few years it will invade again, knowing that ultimately the spineless West will hand Ukraine on a plate to them a second time. Maybe they will attack more countries like Georgia, Moldova, even the Baltics.
Why wouldn't they? They have demonstrated they want more land. If everyone in Europe and America is happy to just let them have it, why wouldn't they take it? Where exactly do we draw the line on what sovereign territory is not sovereign enough to be carved up and given away?
It is better not to incentivise Russia to engage in aggressive behaviour if we want the fighting to stop and for borders to be respected. Appeasement will ultimately invite more aggression, and that could actually bring Russia closer to the West's actual red line, and that is when WW3 begins.
And believe me we don't want that.