We live in an era of global migratory potential — a time when a vast number of people have the physical capacity to move relatively quickly and easily between states. In this article, I use this fact to motivate a powerful objection to ‘statism’, the view that the egalitarian principles of justice which apply to citizens have no application outside the boundaries of the state. I argue that, in a world characterized by global migratory potential, the supposed contrast between the (...) normative standing of citizens and non-citizens on which the doctrine of statism depends is much harder to establish than proponents of the doctrine seem to realize. Focusing initially on the well-known justification for statism based on the notion of reciprocity between cooperators in a joint venture for mutual advantage, I argue that non-citizens play just as important a role as citizens in upholding schemes of cooperation, and that non-citizens should therefore be included in the scope of egalitarian justice along with citizens. I then go on to explain why the problem raised by the fact of migratory potential threatens to undermine not only the reciprocity-based conception, but all other conceptions of statism. The challenge for the proponent of statism is to show that the relationship in which each individual citizen stands with the state is not only a justice-grounding relationship, but also one in which no non-citizen stands with the state. The challenge has not been met so far, and I argue that it is unlikely to be met in the future. (shrink)