this is an old neonazi tactic, winter war propaganda is very popular where holocaust denial is outlawed. it’s very confusing and muddied the most important thing to remember is that this is nazi propaganda and that it’s popular because it’s confusing as shit. If it was very clear cut which side finland was on it wouldn’t be a major focus of neo nazi propaganda. So rather than get bogged down in all the infinitesimal details just call them a nazi. dont start in with a reasonable argument going “finland was this that or the third thing” they don’t care and you’re just falling right for their trap.