The Ukrainians will decide what to sacrifice and what not to.
However, this is a civil war between Eastern Ukrainians that are ethnic Russians, and in the Russian Sphere of influence/control and Western Ukrainians that are ethnically mixed, and in the Western Sphere of influence. It is also a Great Power Competition by Proxy with NATO on one side, and the Russians on the other.
If Russia loses Ukraine, the strategic depth to Russia that enabled them to grind down the Wehrmacht, and Napoleon's army with their prominent allies General Winter and Colonel Mud, will largely be lost. Given how much they have to lose I will be suprised if Russia does not head towards full and complete mobilization of their entire nation.
The only reason Russia is losing anything at all, is because Putin chooses hostility. Before Putin, relations between Russia and NATO were quite warm. There have been joint exercises, and there was even talk of Russia joining NATO. Putin chose otherwise, and that's hurting Russia.
Russia would do well to get rid of him as soon as possible, and replace him with someone more reasonable and interested in peace.
It is definitely a civil war.
Hit squads from the West were operating in the East, and the Ukrainian Army has been bombing, mortaring, and rocketing civilian and non-military targets back in 2014.
A good example is https://www.youtube.com/watch?v=pooFkZzmtNc in Lugansk (warning, this is very graphic) also covered under https://www.osce.org/ukraine-smm/119479
> Those separatists are mostly Russians acting on Putin's orders. I don't think there was ever a majority in Donbas for independence or joining Russia. The only reason the separatists got as far as they did, is because they were entirely propped up by Russia.
When I've been in Ukraine pre-coup and pre-war, the Western part is completely in the European sphere, and loosely connected to Russia. Sure, they may speak Russian, Ukrainian and some English, but they think of themselves as Ukrainians.
Eastern Ukraine is really little Russia, ethnically, language, culture, economics, all Russian. One of the guys I know there, prior to everything w. the coup and all that, just uprooted and moved to Moscow. Of the friends there, many held Russian passports, with family in Russia.
Go back to Russia (Polagaya, chto tak ne svjazan v Glavset, kak horoshij pes, kotoryj ty est'.)