Alex WellersteinVerified account

It has never shown up in any Soviet archives, and there are no substantiated hints that it did. On the balance I suspect not.

There have been some former spy-types who claim it might have, but former Soviet spies often not reliable on such matters. No real evidence.

Additionally: the general history with Soviet post-Cold War spy stuff was intel agencies claiming credit for nuclear work.

One would imagine that if they could claim to have gotten the USSR the H-bomb — and thus devalue Sakharov's contributions — they would have.

I once asked Edward Teller the extent to which the USSR H-bomb relied on espionage. He insisted it was all Sakharov, not spies.

Sure, but would he know that? He had a definite agenda there. Teller's argument was always that H-bombs were easy for scientists to make.

Hence, in his mind, it was criminal that Oppenheimer et al. had said they shouldn't/couldn't work on them originally.

It was people in the pro-Oppenheimer camp (like Bethe) who insisted that they were difficult, that Teller (or Ulam) was a genius, etc.