I'm not privileging it as anything other than real-politik. Ukraine doesn't really have a say in what happens on the extremes of its potential policy, it has to find a comfort zone between the poles. It should be able to choose its path, but it can't. The decision makers over Ukraines future are the US and its allies and Russia. Russia will view a unified Ukraine under the current government as a clear and present danger to national security and it will therefore leverage its strength against that happening. It will maintain buffer states in Eastern Ukraine, and if the tide turns against those states, expect a swift Russian escalation.
Russia in this case holds the strongest hand, the USA cares about Ukraine only to a point, likewise with NATO. The government in Kiev wants to severe ties with Russia (it has), it wants closer relations with the west. It is also extremely hostile to Russia, and Russias strategic concerns trump this, not because of privilege, or morality, or ideology, but rather because Russia will squash Ukraine if Ukraine threatens Russia with further NATO encirclement. The only question here is, is the US willing to go to war with Russia over Ukraine (unlikely worst case scenario), or (more likely and more immediate) is it willing to risk Russia suddenly supplying state of the art Ruskie arms to the various rebel groups fighting US and NATO forces around the world? In a tit for tat escalation.
If Canada suddenly went hard socialist, and broke as many economic and political ties as it could with the US in favor of China, what would the US response be? Should Canada be allowed to do this? Sure. Could it happen? No. Would it happen? The US wouldn't allow it to. Canadian foreign policy in this regard is much like Ukrainian, in that Canada's foreign policy is dictated by the fact that the US will prevent Canada from going to one extreme or another that would threaten US national security. The US also doesn't have a history of being invaded in the last 2 centuries to the cost of 50 odd million dead, which Russia and the USSR did. This is something, Crimean War, Napoleonic War, WW1, Russian Civil War, WW2, these are wars that have shaped the very foundational identity of Russia and Russians. Their concerns over their history are no less valid than the concerns of Israel and its right to exist in Palestine, a vast historical trauma has shaped their national identity and when you deal with Russia you should be cognizant of that. This is why we have a losing hand in Ukraine. Russia will go to the wall on this, we won't, so why are we pushing.
I see it as a continuation of fear politics that have dominated US domestic policy since WW2, or perhaps even earlier. If we don't have an enemy we create one, in an effort to justify or perhaps feed the military industrial complex. The US economy needs that rival, or that enemy to justify the defense spending. We also view a resurgent Russia as a threat to our economic hegemony outside the Chinese sphere, so undermining and destabilizing is standard operating procedure. We moved NATO to the Russian doorstep along the majority of its European border when Russia was in no position to resist, but now they are and they will. Whatever the motivations are on either side are ultimately irrelevant. It's a case of "Not what you know, but what you can prove" applied to "It's not what your motivation is, but what you can justify". Putin can justify intervention in Ukraine because of the historical fear of invasion and the real fear of NATO encirclement. With that, he can justify anything, and we in the west have only solidified that justification with our own interventions around the world in the last 75 odd years in the name of national security. It isn't a case of whataboutism, it's a case of historical, legal and moral precedent. If we have done it, they can justify it based on that pretext, and also the fact that the Russians/USSR have never openly intervened militarily on any country they didn't share a border, which NATO cannot say.
You're right, but you're also wrong. It may be just about drumming up nationalist support for his "elections" but that doesn't really matter, because he doesn't have to twist the knife very hard because everything he could potentially do in Ukraine is going to be absolutely justifiable to Russians, and internationally anyone who condemns him for acting on the fears of his population which me may or may not be exploiting for political gain, are massive hypocrites if they come from a NATO country. Again, this isn't whataboutism, it's about justification. His population will want it, that is his domestic justification, and the precedent for interventions based on national security fears is something that is well and truly established by the US and the UK, the rest of NATO and even pre-dating NATO.
All that really will matter is, can he justify it to his people? Yes. Is it justified based on the current political climate we've established as de-jure? Yes. Does it suck for Ukraine? Yes. Should Ukraine be entitled to complete self determination? Yes. Will Ukraine be allowed complete self determination? No. Why? The previous 5 paragraphs explain why