You mean like North Vietnam? Or Vietcong?
Yeah, I said before that I theoretically could see Russia achieving "victory" by either hard winning the propaganda war or using nukes, when I say it's impossible for Russia to sustain the war effort longer than the West, I mean it assuming situation continues as it did for the last few years, and nothing groundbreaking happens.
My definition of Ukrainian victory ofc doesn't involve them pushing into Moscow or even getting their occupied territorries back, because that was never going to happen - just as Russia has no hopes of doing any better with their offensives than before, Ukraine is incapable of pushing their positions. One thing this conflict showed is that people in this modern age feel entitled to peaceful lives, and even authoritarian imperialistic countries like Russia or countries fighting for their sovereignty like Ukraine, are unwilling to spend too many lives of their soldiers, afraid it would bring the end of their rule.
The conflict lasted for a few years now, but casualty numbers are EXTREMELY low compared to past conflicts we've seen, and it's unlikely to change. Either side could go for a WW2 style conscription and mass assaults, and probably easily push the current frontline in the short term, I'd say Russia could even probably achieve decisive victory if they went with drafting millions of soldiers and just throwing them at Ukrainians, accepting the few millions of lives they would have to pay for it, but it's obvious at this point they are completely unwilling to do so (for a very good reason).