And flagrantly violating every agreement that has ever been made w/r/t Ukraine. And killing political opposition with impunity. And giving medals to every soldier in the units stationed in Bucha a few days after of the massacres were uncovered. And "annexing" regions of Ukraine where your soldiers haven't even reached, and putting them on official maps of Russia.
And using chemical and radiological weapons to conduct assassinations on UK soil. And blowing up Czech ammo depots.
And telling the world that if there were any Russian soldiers amongst the "little green men" in Crimea, they were merely on vacation.
And this trash: https://www.bbc.com/news/technology-60562240.
There's a reason non-western aligned countries are a bunch of corrupt shitholes, they want more serfs to do their bidding and the west is showing their population what their life could be and ruining their plans.
Study the outrage in the USA when Russia put nuclear missiles in Cuba, when Cuba, a sovereign country asked for those missiles (aka The Cuban Missile Crisis). Substitute Cuba for Ukraine and USA for Russia and you will be begin to understand the Russian point of view. But hey the West is Right, We are the Good Guys, always on the side of Freedom and Democracy so we can't be wrong. Just ask the Palestinians in Gaza.
You haven't considered the consequences of folding to nuclear blackmail. That increases the chances bad actors will use nuclear blackmail again (because you've shown it works), and it increases nuclear proliferation because small states start feeling unsafe if larger states refuse to help them defend themselves out of fear.
Also Russia: "NATO pinky promised in a discussion between two people no one remembers that it wouldn't expand East, so we're invading Ukraine and threatening you with nuclear war"
My heart goes out to the Ukrainians, who are fighting determinedly not to be liquidated by Putin's mafia state. But the Dick Cheneys of the world couldn't be happier that Putin decided to invade.
He has threatened Sweden directly with nukes if we ever tried to join Nato for instance.
And even then, Putin has no limits. We cannot continue to put red lines and limits on ourselves when the opponent doesn't have any.