My recollection is that concepts such as the political disposition of the Moon, etc, are enumerated under various United Nations treaties.
Like the Altairians care.
When the Altarians establish a US -based spaceflight corporation and / or engage in flights from US soil, then they will care. If they don't, then they will find themselves in violation of FAA rules just like anyone else.
Yeah, that's right. They set the rules for occupying the entire universe. Sort of like the Pope.