This chapter examines democratization, “failed states,” and empire building after the East–West conflict. The debate over “democratic peace” focused on democratization and was being underpinned by the vision of peace developed by Immanuel Kant in 1795. Since the end of the nineteenth century, there had been no serious discussion of Kant's ideas on how to achieve peace. Power–political realism, liberalism, and modernization theory, which were based on assumptions quite different from those of Kant, were far more prominent. It was only in the early 1980s that this changed, with global political developments and new political circumstances playing a crucial role in the resumption of the debate on Kant's ideas. The immediate trigger for this debate, at least the academic variant, was the two-part essay by Michael Doyle from 1983 entitled “Kant, Liberal Legacies, and Foreign Affairs.” The chapter also considers the relationship between international relations and sociology.