Refugees pose a challenge to the state-centric order of international law. They move, while the state, seemingly, remains fixed. States have accepted obligations to protect human rights within their boundaries, and they have retained the right to police those boundaries. A potent fear that the floodgates will open and all who seek adequate or better protection of their human rights will move to more privileged states has stymied the development of complete freedom of movement. Whether despite or because of this fear, the right to exclude aliens is posited as a right founded not on privilege or power, but on morality: states need to protect, respect and ensure the rights of citizens, and their capacity to do so might be adversely impacted by unfettered immigration.