What, except maybe that states are immoral and opportunistic, does these things tell us?
I am not sure. Maybe I am missing net positive things as outcomes from these behaviors. But to me neither example is good.
The German / Austrian / Hungarian scientists that worked on the bomb came to the US years before the Manhattan project started.
I remember my professor at University arguing against the fact that this idea was presented as proven fact, when there were many question in the scientific community.
Not sure how maybe newer evidence might have changed it. I would need to dive into the actual scientific literature to update my knowledge of the topic.
If you dig into the history it’s pretty interesting. The USSR and France I believe were adamant about de-Nazification, but petered out quickly when they realized it was holding up rebuilding the country. The US and UK weren’t too worried about lower level Nazi’s once the leaders and major war criminals were handled.
Moreover the DDR cannot seriously have had such concerns, since it too e.g. employed former Nazi officers in its army.