In a conventional war sense the Ruskies do hold the winning cards. But in a guerilla war, where just about every Uke wants to kill them and have the means to do so, the Ruskies won’t last long.
As long as the Ukes remember what Stalin did to them years ago it won’t take much to motivate them to put a target on every Ruskie soldier and try and kill them.
Let it be their second Vietnam, but I don’t think it’ll sell well with the Russian populace once they see their boys dying in large numbers.
Would Ukranians wage the kind of war the Vietnamese and Syrians wage? A guerrilla war means being willing to accept ten to a hundred losses for each loss for the occupier. Would a European nation these days be willing to accept those kind of losses? Also a good chunk of Eastern Ukraine would support the invasion since they are Russians, any guerrilla war would also be a civil war.
Russians will not fold easy, they have alot of fresh experience fighting guerrilla movements in the Caucus. Chechens are born and bred to kill and are pound for pound the most vicious killers in the world, so I think Russia is more than prepared for that kind of conflict.
I don’t like the idea of Europe turning into a battlefield again after almost a century of relative peace.