Japan has JAXA
The UAE have a space agency that even has a Mars mission running currently.
Same for China.
There's more I'm forgetting, but space stuff is not limited to Europe and the US.
Also to be fair a lot of US defense and aero contractors have manufacturing partnerships around the world.
No.
For example in university i was part of a satellite design competition. We couldn’t let Chinese nationals on the team or we’d be breaking the law. There was a list of approved countries a team member could have citizenship from, if not we’d be guilty of violating export controls.
Satellites are considered munitions… working on a foreign power’s weapons programs is… discouraged.
I got bad news for you. Their spacecraft was built by University of Colorado at Boulder.
[1]https://en.wikipedia.org/wiki/European_Union_Agency_for_the_...
Alternatively, many of the private space companies don't have citizenship requirements.
In America at least private companies are equally covered by ITAR, so they do have citizenship/greencard requirements (or need a variance that is nearly never granted in practice). SpaceX can't just hire international talent as it wishes. I assume there may be similar rules in some other countries, though certainly not all. But it's not merely a matter of private vs public fwiw.