First sentence heavily implies American law. Secondly, international law is part of American law. en.wikipedia.org/wiki/The_Paquete_Habana

The lawsuit is actually making an equal protection argument, though, which seems like an enormous loser. The government isn’t refusing to evacuate somebody because of their race or religion — which would be the essence of a disparate intent equal protection claim. They are unable to evacuate someone because the local government refuses to allow it.

Maybe the plaintiff can try to make a disparate impact claim but I suspect the courts won’t want to hear it given the facts.