[deaddodo]

Where did you get this idea? There is a ton of intelligence the US had gained from its intelligence community, along with a ton gained from allied intelligence agencies. There's an entire category on Wikipedia dedicated to well-known defectors[1] and spies[2] in the USSR.

The reason you hear less about it from a Western perspective is because the Western allies leveraged reconnaissance technologies more efficiently. They had better aerial reconnaissance, a wider satellite network (from the late-70s onward), nearer proximity to Moscow, wider military projection and better code breaking. It is well-accepted that the Soviets, and the Russian successor state, have always had a hell of a time keeping encryption secret long from the combined US, Commonwealth, Israeli and German intelligence.

While the West didn't know everything going on inside, they were able to see almost everything from a birds eye view. It was necessary for the Soviets to have an extensive spy network to get the equivalent viewpoint.

1 - https://en.wikipedia.org/wiki/Category:Soviet_intelligence_p...

2 - https://en.wikipedia.org/wiki/Category:American_spies_agains...