I think the US is just adding a self-imposed constraint that hinders their own progress. Other nations have built ICBMs and have space launch capabilities too.

I think the US is just adding a self-imposed constraint that hinders their own progress. Other nations have built ICBMs and have space launch capabilities too. The US is not significanltly "ahead in the game" and their development is slowed down by hiring US citizens only in the aerospace industry. Not all rockets are practical as ICBMs. ICBMs tend to use storable (hypergolic) propellants so they can be maintained and ready to launch at short interval. Many space launch vehicles, such as those built by SpaceX, use cryogenic propellants and need to go through a time consuming (and dangerous!) propellant loading before they can be launched. (note: the Indian and the Chinese space programs use primarily solid fuel and hypergolic propellants) I'm sure SpaceX, ULA and others would be happy to recruit non-US citizens if the regulations didn't disallow it.