Chapter 3 seeks a justification for states’ claims to have rights to self-determination that entail the right to control admission to their territory. States assume they have certain rights (such as rights to admit and exclude from their territory) and that agents of the state may act in ways that privilege the interests of their citizens. What justification can be offered for these arrangements? Importantly, what compelling justification can be offered to those who currently find themselves beyond those borders and who wish to cross them? In seeking a justification, we discover that for states to have robust rights to self-determination within a state system, they will also have many responsibilities. A state’s ability to exercise political power legitimately depends on its respecting human rights adequately and cooperating in a host of trans-border activities and institutions that have as their aim securing robust arrangements capable of effective human rights protection. Performance on both these dimensions affects whether we have a legitimate state system, along with whether there are adequate contingency arrangements in place to deal with important shortfalls.