PBS did a great documentary of Nazis in the US pre-WWII
https://www.pbs.org/wgbh/americanexperience/films/nazi-town-...
It elaborates on your point about the large US Nazi presence.
Not quite; that requires equalities; the Nazis and that version of Japan were not nearly equal in their evil or atrocities to the Allies. My point moreso was that the Allies were doing a thing in war we don't do anymore, which is matching force with force - which today is illegal. We have the Geneva Convention that stops us from doing that anymore. Now of course, late in the war we discovered the death camps and that is the post-hoc rationalization that I'm referring to but nonetheless the Geneva convention is a byproduct of the shock of what it took to win. It more or less attempts to put a ceiling on the ferocity of war.
I'm sure there's more examples, but the only allied case I can think of was a soldier convicted for hiding in an ambulance and shooting from it.
There was a strategic decision not to charge Nazis for the bombing of London.