Carson Mark: We shouldn’t have been making this damn bomb without trying to keep it secret from [Joseph] Stalin. We should’ve been talking to him like [Niels] Bohr said. [Klaus] Fuchs believed and took it into his own hands to make sure that the conversation went on. Of course, he didn’t need to because Stalin knew anyway. Not the technical details, but the general facts.
George Cowan: What you’ve learned from the Russians, for example?
Richard Rhodes: The main thing I have learned is that their first bomb was a carbon copy of Fat Man.
Cowan Cowan: Well of course. I knew that in 1949, about the middle of September of ’49 because we analyzed the debris from that and it was clear that it was a carbon copy.