ukraine has a very weird history with nazism. one might expect ukrainians to be reflexively opposed to an ideology that ranks exterminating them to generate lebensraum as one of it's primary priorities, but the ukrainians were fighting against stalin, and they wanted to get rid of their own jews, as well. if the nazis had actually managed to win against russia, the ukrainian nazi collaborators would have been the first to go. you can't really make sense of it other than trying to put your self in a position where you have to choose between hitler and stalin and cannot choose a third option. it's one or the other, and these ukrainian groups were going to end up dead, either way. would you rather be killed by hitler or stalin? it's beyond faustian; it's more like a mass shooting in modern america, followed by imminent suicide.
it doesn't make sense, but it's real: there are a lot of nazis in ukraine. this guy was organizing them. he had to go.
like they say - the only good nazi is a dead nazi.