Migration is not solely "Germany's crime."
Post WW2 Western "deNazification" pressured Germany into proving it's no longer racist, making them adopt some of the first "hate crime" laws, having their schools pound "anti-racism" into the heads of every German child.
Hollywood and the BBC (among others) have for decades produced an endless stream of German accented villains in entertainment, further pressuring Germans to prove they're no longer like that.
Then there are all the "anti-racists" in Britain, France, and other countries, who (without any German pressure) are welcoming migrants and punishing those who object.
Then there's the American Global Empire and its NATO and CIA, which further pressures Europe to open its doors, threatening a color revolution against countries (e.g., Hungary) which refuse.
No, this is not solely Germany's crime. Not even mostly German's crime.
No question the allies forced the Germans to take in millions of Non-Germans so that another Hitler would never rise again.
“Migration is not solely “Germany’s crime.””
Never said it was.