There has been extensive non-partisan (historically accurate) analysis of this, which I won't repeat here because it just invites the wrong kind of nit-picking debate over minutiae that don't matter.[1]

Meanwhile, actual fascists and literal NAZI party members took over most of Europe in the 1940s. Italy was fascist. Austria joined the NAZIs. Hungary did too. Hungary is turning increasingly fascist right now and Russia loves this: https://theconversation.com/i-watched-hungarys-democracy-dis...

Apparently, that's no longer a problem, but a single long-dead[1] collaborator with no real impact on Ukraine even when he was alive is apparently reason to invade with... drumroll... a merc army lead by a neo-NAZI with SS tattoos: https://aijac.org.au/fresh-air/russia-sends-its-pet-neo-nazi...

You can't make this stuff up. If this was a script for a movie, the author would be laughed out of the room.

Sigh.. the whole "Ukraine is NAZI" talking point is just that. An excuse, a throw-away comment that works on Russians and nobody else. It's like the bully that punches the kid in the playground because they wanted to, and when asked, comes up with some "reason" on the spot, like "Oh, I didn't like the way they looked at me" or somesuch.

[1] A favoured argument tactic by those people who know they're in the wrong with respect to the fundamental points. Ukraine could have been 100% NAZI and saluting Hitler in school, but this doesn't matter if it occurred when 80% of the current population hadn't even been born yet!

[2] In the dirt for more than half a century now! Bandera died in 1959! that was 63 years before the start of the current invasion. THIS is my point precisely, that Putin's justifications are out-of-date, based on politics that have zero relevance to modern-day Ukraine.