Includes bibliographical references and index.

"In modern times, international borders reflect discontinuous changes in political authority, no matter what the inconveniences are for the individuals that they separate. What explains this fact? Why are the citizens of neighboring regions that happen to lie across an international border often subject to very different governance systems? We argue that the defining feature of the modern territorial state system is the local, bounded, monopoly that states have in governing their citizens. States refuse to violate each other's monopolies, even when they could do so easily. We examine what makes this system stable, when and how it emerged, how it spread, how it has been challenged, what led it to be so resilient over time, and how might it change in the future"--