See also: citizenism, local inequality aversion, and second-class residents.

Territorialism is an ethical principle that says that one should give greater moral weight to the interests and preferences of those who are within the boundaries of one’s geographical region than those outside. It is a slight variation on citizenism. The key difference is that while citizenism uses citizenship as the litmus test of moral worth/concern, territorialism uses residence as the litmus test of moral worth/concern.

Territorialists are more likely to support enhanced rights and privileges for existing immigrants (legal and illegal) and guest workers residing in their country. But they may agree with citizenists that further immigration can be stopped on the grounds of harms to those already within the country (though citizenists would focus on harms to citizens, territorialists would also consider harms to existing non-citizen residents) even if those harms are not as severe as the benefits that immigration confers on immigrants.

Reading material on territorialism and its relation with immigration restrictionism

"The Efficient, Egalitarian, Libertarian, Utilitarian Way to Double World GDP" — Bryan Caplan