For Nazi history in US buffs like me, a very interesting report by Commander Kenneth T. Klima, U. S. Navy was put forth in 2024 in the form of an MA thesis at Harvard University.
The effectiveness of Nazi-era espionage in the US had been downplayed. But his review of a declassified intelligence batch in the early 2000s appears to tip that over.
Read Full Article: https://armedforces.press/history/2026/01/25/nazi-spying-in-us-was-more-effective-than-previously-thought/
