States, cities, and border control: Do sub‐state collectives have a right to protect vulnerable people on the move?

Abstract It is beyond doubt that states everywhere practice discretionary border control. However, in normative political theory, there is vigorous debate about the justifiability of this practice. Some theorists appeal to border crossers’ interest in free movement, envisioning an open borders utopia, while others emphasize the value of collective self‐determination, defending strong border control rights for states. Both perspectives focus on two primary interest‐holders: state collectives and individual border crossers. This analysis offers a novel perspective by arguing that cities—and sub‐state collectives in general—may also have significant interests in immigration policy. Through empirical examples like Europe's “Solidarity Cities” and North American sanctuary cities, the paper argues that cities often possess self‐determination–based rights to protect an additional quota of vulnerable border crossers, beyond those their state protects. This conclusion is surprising because appeals to self‐determination typically defend a state's right to limit migration. Yet, it is one that proponents of the self‐determination view have reason to accept.