Well, I'm not saying it isn't totally BS; but I understand the motivation to overturn every stone when talking about defense. It isn't like the US didn't surprise a country with new physics during WWII.
It wasn't exactly 'new' physics, it was an application of a theory built on established physics. The surprise wasn't that it was possible, but that it was technically and economically feasible.
Japan apparently had their own atomic bomb project[0], but the military didn't consider it a priority so funding was scarce, and it was difficult to secure enough uranium.
The Germans also worked on an atomic bomb during the war. Heisenberg was in charge of the Science. They had an institute in Heidelberg dedicated to it and several other sites. The calculation for the order of magnitude of required fissible material was off by 1, which might or might not have been a deliberate error. Furthermore there was no good source of uranium as far as I know discovered in Germany at the time as far as I know.
