In this paper (which is a chapter from a book manuscript on the ethics of immigration), Carens explore the principled challenges to open borders that grow out of concerns for community. He begins with the claim that our moral commitments to freedom and equality apply only within the boundaries of the state. Next I consider the relationship between sovereignty and immigration. Carens then turn to the threats that some say free movement would pose to national security, to democratic values, and to public order. After that, he considers the argument that opening borders fails to give the priority that is due to compatriots. Next, he asks whether preservation of a welfare state might make limits on immigration morally permissible. Then Carens considers whether the desire to maintain a shared culture can justify restrictions on immigration. Finally, he take up the argument that free movement is incompatible with communal self-determination and with the shared responsibility that flows from collective self-governance and sustains it.