Self-determination is a central concept for political philosophers. For example, many have appealed to this concept to defend a right of states to restrict immigration. Because it is deeply embedded in our political structures, the principle possesses a kind of default authority and does not usually call for an elaborate defense. In this paper, I will argue that genealogical studies by Adom Getachew, Radhika Mongia, Nandita Sharma, and others help to challenge this default authority. Their counter-histories show that the principle (...) was used to justify, strengthen, and adapt imperial rule in the twentieth century. In particular, the idea that controlling a population's composition through regulating immigration is an essential aspect of self-determination emerged as a response to White anxieties about the migration of negatively racialized groups. Genealogies have not been adequately appreciated as a critical tool within the mainstream of political philosophy. I show that these genealogies have a critical role to play because they unsettle our uncritical attachment to the structures of the nation-state system and raise serious questions about the meaning and emancipatory force of the principle of self-determination. (shrink)