Oppenheimer, as well as many other Manhattan Project researchers (eg Rabi & Weisskopf), were first or second generation German-Jewish immigrants/refugees. Max Bonn, Oppenheimer’s mentor, was also a refugee in the end; Oppenheimer was born to immigrants in the US but studied under Bonn in Germany prewar.

Moreover, the physical foundation for atomic power was largely the work of German, often German-Jewish, scientists.

So it’s plausible to suppose a counter-factual in which Germany, one less crippled by bigotry (and it is a disability…), develops the bomb.

And it’s not just the bigotry: it’s the anti-intellectualism. Einstein could write a letter to a well-educated patrician of the New York Dutch aristocracy (FDR), and so help change the world. The pig farmer and the corporal would never have read such a letter (even if were they not already trying to murder the writer and all his cousins for nonsense reasons).