Do employers have some kind of ethical obligation to employ their countrymen (as opposed to outsourcing)?
One might make a Kantian style argument that it is unethical to 'use' one's countrymen by using the local resources and the education you received within the community to start your business, but then outsource the overwhelming majority of the work (and the implicit benefits) to a different community based strictly on cost once your business is successful. I think the argument is plausible, but I don't find it ultimately convincing. The argument might be strengthened by revising the conclusion. Instead of making the blanket judgment that outsourcing is unethical, one might claim that one is obliged to weigh the benefits you and your business have received from your community of origin as one important factor when deciding whether to outsource (and perhaps how much to outsource if you decide to).