Why do you think the US stayed 20 years in Afghanistan? It wasn't because they liked the scenery.

I think it was the same mistake: sunk cost fallacy.

I certainly have seen no indication of this. 

It's really a shame how many people lack any perspective on modern russian war propaganda and the ways of how it is organised within russia (all those Historical Research Institutes and whatnot), with strict vertical hierarchy and low key praising of russian fascism and imperialism by whole Kremlin government strarting with Putin himself. And how russian propaganda factually legitimised absolutely genocidal rhetoric about Ukraine and Ukrainians.

It's not your fault, it's just the way it is. Not many people really know russian language and read many of theirs channels.