Sovereignty is one of the central organizing concepts of modern Western political thought. To say that it is a concept central to the organization of political thought is not to say that it is one of the concepts on which political theorists have lavished the greatest amount of explicit attention. But it is to say that certain claims about sovereignty are crucial to the way philosophers in the modern period have modeled or pictured the political world about which they are theorizing. That way of picturing the political world gained currency following the Peace of Westphalia, which was brokered to end the wars of religion that wracked Europe after the Protestant Reformation. It can therefore be called the post-Westphalian model.

The Peace of Westphalia gave impetus and sanction to the emergence of national states in Europe. The post-Westphalian model is a model of the world of...