I think the moral of this story is that all empires fall and most fall quickly. That Putin in his arrogance chose to attack Ukraine where the people there have fought fiercely for not only their freedom from Russia but to avoid genocide only accelerated the process. Putin's attacks on Georgia and Chechnya gave him confidence that Ukraine would roll over as well and no doubt his advisors told him what he wanted to hear.
The USA is facing the same scenario and their own hubris has prevented them from learning anything from their misadventures in Korea, Viet Nam, Lebanon and recently, Afghanistan- the graveyard of empires. When the American empire ends, it will probably do so, not with a bang, but with a whimper.