"foreign-owned" in this case is still the UK i.e the closest ally we have today. So I don't think you'll see the same sort of American protectionism you might see with e.g a Chinese competitor.
Therefore... yeah, nothing's stopping the DoJ (guessing the FTC would make the referral?) from pushing an antitrust matter. But I certainly can't say for sure; I'm not a lawyer.
Foreign owned maybe, but the satellites are manufactured in the US. There are US commercial interests at stake in Oneweb, and the services it intends to offer to US clients too.
> Where's the law that says that an American business must sell their product or service to a foreign company?
As I understand it, it's covered by the various antitrust laws in the United States. And it's not so much a "foreign company" thing so much as it's an unfair advantage for any one company thing. https://en.wikipedia.org/wiki/United_States_antitrust_law
Again, not a lawyer. But my lay reading would say that it would feel comparable to the action the feds took against Microsoft for trying to stifle Netscape. But I'm sure there are far better analogues.
Therefore... yeah, nothing's stopping the DoJ (guessing the FTC would make the referral?) from pushing an antitrust matter. But I certainly can't say for sure; I'm not a lawyer.