Please correct me if I'm wrong, but from what I understand the fraud was aimed at US [particularly Californian] emissions regulations but not German/EU emission

Please correct me if I'm wrong, but from what I understand the fraud was aimed at US [particularly Californian] emissions regulations but not German/EU emissions regulations, which differed in such a way that cheating wasn't necessary for those engines to pass. The American emissions regulations were more concerned with nitrogen oxides than the EU regulations which emphasized fuel efficiency; Volkswagen found they couldn't satisfy both at the same time (or would make less money if they did?) so they chose to make efficient engines that produced a lot of nitrogen oxides, then use cheat software to evade the nitrogen oxide regulations in America. If my understanding of that is correct, it doesn't surprise me that German authorities weren't very proactive about a German company defrauding the American government. It obviously disappoints me, but it doesn't surprise me.