A Russian defeat won't make it a more civilised nation, not even in the long run. On the contrary, they'd dug in, grow more bitter as the defeat made them poorer, which, on the other hand, would increase it megalomania and sense of historic mission, only to strike again.
True, every major country with a sense of purpose and destiny finally had to give up on these due to a military defeat – Japan, Germany, the UK, Spain, France... all empires turned nations after military defeat ended their sense of destiny. (Which, by the way, is why the U.S. still rolls in its sense of glory and purpose.) A nation that relishes in power and glory needs a defeat from oustside for a chance to leave its sense of mission behind.
But that is not all. China overcame defeat, Russia will too. What distinguishes both from say Germany and Japan after WW II, is that the victorious powers occupied the land and engaged in training people and bureaucratic layers to adopt representative democracy, liberal values ("liberal" not in the sense of "progressive" but as in "egalitarianism"), a market economy more or less balanced with social welfare. Russia doesn't have that nor will it have it in the future. Revanchism is thus the prospect (like Germany after WW I), not the embrace of good citizenry. (And the U.S. doesn't have these things either which is why it is deemed by so many the most dangerous country in the world.)
As much as I would like to disagree with this pessimistic assessment - I'm afraid I can't. Fortunately, nobody can see into the future, which may still give space for unexpected developments. So far, however, the war has brought little surprises, at least not for those who knew a little bit about Russia and Ukraine.
What do you mean by "the U.S. doesn't call Vietnam, Iraq, or Afghanistan (or wars sometimes)"?
Anyway, the U.S. glorifies its wars as Russia and the former USSR do/did. My point is that only when empires (or wannabe empires) were decisively beaten by foreign military forces did the megalomaniacal sense of destiny and superiority vanish. Japam, the UK, France, Spain, from its ambitions even Geermany, all turned "moderate" and gave up their sense of "being the fate of the world". The US has never been beaten that decisively. And Russia, although probably being beaten, will not be beaten on its own soil and will spin its defeat in the sense it always does: Being a grand nation, but always being subdued by foreign nations that want to prevent Russia from its place. It's a centuries-old paranoia.
@simsa04 So your theory is that the U.S. doesn't call Vietnam, Iraq, or Afghanistan (or wars sometimes) because it would cause their people to realize they don't have athurotiy over others?