I will always support self-determination. Ukraine was obviously justified in wanting to join BUT you cannot expect a country that counts casualties in the millions every time it gets invaded to not get its hackles up about a nuclear armed alliance specifically aimed at containing it expanding up to its doorstep.
I look forward to seeing Putin on trial in the Hague, but if you're not willing to do a hard-headed logical analysis of the situation then you're doomed to watch history repeat itself in an endless cycle.