A distinctive feature of the evolution of the modern international system has been the emergence of ideologies so universalist in their assumptions that they have ignored, or worse, denied the cultural and political diversities of mankind—diversities which constitute the ineluctable framework of international politics and which make the conduct of foreign affairs such a complex and difficult craft. One major obstacle, however, to understanding the problems which this development poses for the theory and practice of international relations is the fact that the correct usage of the term ‘ideology’ is very much broader than that which is generally accepted today.