In a sweeping account, Philpott argues that transformations in ideas about justice and political authority have given shape to struggles over state sovereignty at such critical historical turning points as the Westphalian peace settlement of 1648 and the colonial independence movement of the 1950s and 1960s. These revolutions outwardly reflected the dynamics of power politics in which empires, nations, capitalists, and colonies struggled to establish their dominance. But the norms of sovereignty did more than simply accommodate changing material structures of class, technology, and the balance of power. They also reflected what happened behind the scenes, as thinkers and activists advanced ideas of justice that eroded the legitimacy of existing principles. In turn, this "crisis of pluralism" opened the way for revolutionary change. Thus the enshrinement of state sovereignty at Westphalia would not have been possible without the changing beliefs about political and religious authority among the Swedish Lutherans and Dutch Calvinists who fought against the Roman Catholic Church and the Holy Roman Empire. Likewise, the colonial-independence revolution stemmed from the ideas of colonial nationalism purveyed by developing-world intellectuals and European liberals. This convincing portrait shows how power and ideas together shape international relations.