It's about as believable as a country with history involving the Third Reich and Stasi openly standing behind a country that the UN, and every relevant scholar on the subject, confirms is committing genocide.

In other words, it's very believable. It is incredible how billions of hours have been spent on Vergangenheitsbewältigung, and nothing has been learnt. Potentially the best phenomenon in existence at showing that humanity is, after all, so much less intelligent than it believes it is - that even after such a destructive event and so much performative effort at analysis and learning, the key takeaway did not become part of the social psyche whatsoever.