That is why the Russian people today see Ukraine entering an adversarial military alliance (NATO) as an existential threat.
A Ukraine that is politically and militarily integrated with far-right and outright neo-Nazi elements is understandably (at least to me) the ultimate existential threat, as the last time this happened it was almost the end of the Russian core of the the USSR.
It doesn't matter what we in the West think of NATO and Ukraine. It is what the Russians think of NATO and Ukraine that matters. This article explains perfectly why Russians feel the way they feel today about the situation in Ukraine.