[Bendingo]

I've not heard this idea before. Why wouldn't US simply allow the Soviet rocket production to just die?

Please do you have a reference for it?

[gandhium]

As I said they were afraid that North Korea or Iran will snatch their scientists.

So they paid Russians to develop an ISS module: https://www.nasa.gov/mission_pages/station/structure/element...

And they paid them to develop RD-180 engine: https://spaceflightnow.com/atlas/ac201/index.html