[ealgeone]

Soviet infiltration of the US government cannot be overlooked. If they had spies at Los Alamos you know they had spies in the Pentagon as well.

I'd betcha Stalin knew the date and time and strength of all of our invasions in Europe and the Pacific.

[Fred Hayek]

Our hating in the Soviet Union was involved in the development of the Soviet bomb somewhat independently. Much of the espionage at Los Alamos confirmed that the Soviets were on the right path.
As far as the thermonuclear weapon, Sakharov took them directly to the “dry” bomb. Their first was a dry bomb, ahead of our “dry” weapon. The US was still looking at lugging the big Dewar flask based on Ivy Mike.