Those companies are breaking the law. SpaceX was prosecuted for doing that.
Now SpaceX says:
To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR here.
If the position requires a security clearance, they are not breaking the law. Language like this is standard on defense contractor postings that require clearances (this from Lockeed):
> Security Clearance Statement: This position requires a government security clearance, you must be a US Citizen for consideration.
> SpaceX was prosecuted for doing that.
SpaceX was prosecuted for excluding refugees and asylees from export-controlled positions, not cleared positions.
Non-US citizens can't get a security clearance. Permanent residents can at most get a limited access authorization. The SpaceX case involved ITAR, not clearance.
Now SpaceX says:
To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR here.