Russia currently has ~75% of its military capacity committed to Ukraine. Russia maintains its nukes, however, committing that much of its military is risky and will leave it vulnerable to invasion and/or military action from elsewhere.
Those that are fighting do not believe in this war. I don't think many will believe in fighting for their homeland in the event of an invasion if that were to happen.
both sides legitmately accuse each other of being Nazis and both sides legitmately disbelieve the Nazi accusation of the other,
thats the paradox
if you research this you will find it to be true