The world today, Benjamin Barber points out, is “falling precipitantly apart and coming reluctantly together at the very same moment.” While states from Canada to India are threatened with breakup due to fractious nationalist impulses of their peoples, the power of technology and markets is forcing ever-tighter economic integration worldwide. From a common-sense perspective, these two impulses are among the most important processes in contemporary world politics. Yet, there has been remarkably little attention paid to developing a theory of the international system that examines the effects of both. Hegemonic stability theory considers economic integration but not nationalism; the few studies of nationalism as a systemic force play down the effects of economic integration; and neorealism, the most widely accepted theory of the international system, has no room to address either trend. The field is, partly as a result, a cacaphony of voices largely talking past one another.