The moral permissibility of banishment

This essay defends the moral permissibility, as a form of punishment, of banishment, namely the exclusion by a state of a citizen from its territory. I begin by outlining the prima facie case for banishment, consider for whom it may be appropriate, and acknowledge constraints on its permissibility. I then defend banishment against the main objections in the literature to banishment or the related measure of denationalization (stripping citizens of their citizenship): impermissible permanency; excessive severity; ineffectiveness; unfairness to those who are punished and the creation of two classes of citizens; unfairness among states; and that banishment without denationalization is incompatible with the nature of citizenship. I adopt a 'cantilever strategy': if incarceration is permissible notwithstanding a certain objection, so is banishment. In concluding, I sympathetically discuss the view that, despite the moral permissibility of banishment, the power to banish should not be instituted because of the risk of abuse.