Ukraine

Totally. Zero chance Ukraine agrees to this. They would be giving up 250k citizens and 7000 sqare miles that has hundreds of billions in resources in them. You want it Russia? Come and take it.

While this is a historic and devastating tragedy for Ukraine, it's helpful to remember this means Ukraine has already won the war. Russia can never do this type of invasion again, their Soviet stockpile is gone, the war chest is spent, they are a pariah for the next several decades. They are in terminal demographic decline, and they will not be able to re-arm before Putin dies to fight a war of this scale again. It's all blackmail, corrosive misinformation and political mischief for them past this point. Their primary export market for oil and gas are dead, they have become China's vassal, and have assembled a crappy coalition of corrupt allies who only run on bribes and are of limited diplomatic use. They lost Syria, they've lost Iran's proxies Hamas and Hezbollah. They've lost the Black Sea Fleet. They've lost much of their strategic bomber fleet. Once he falls, there will be infighting, as there ALWAYS is when Russian emperors die.

It's kind of comforting to know Putin will die before he sets foot in Kyiv. In many ways, you can consider this the last war of the 20th century. The great, if not-quite-as-envisioned revenge project of the dead idea of the Soviet Union.