What is sad re: Ukraine is that this situation was projected on the military side of things for damn near a decade. I recall an intel report way back in 2015 or so for a detachment I was a part of that summarized this quite nicely, from the energy source concerns on to westernization in-roads being a known concern to the Russian leadership in their backyard. Wasn't classified either btw, as this was known and driven by war college estimates for some time. In fact you can find good briefs to college students around that time frame on youtube that nicely summarize the how's and why's this was bound to happen.
There was always that likelihood that Russia would do this at some point where they felt safe in doing it, and the bottom line is the west is not willing to go to war over a satellite state in the Russian orbit.