This is not only a book in international law. It is also an exercise in social theory and in political philosophy. One of the principal theses of the book is that it is neither useful nor ultimately possible to work with international law in abstraction from descriptive theories about the character of social life among States and normative views about the principles of justice which should govern international conduct. Indeed, many international lawyers have recognized that this is so. They have stressed the need to elaborate more fully on the social determinants of State conduct. And they have emphasized the law's instrumental role in fulfilling normative ideals of “world order”. But they have had difficulty to integrate their descriptive and normative commitments into analytical studies about the content of the law. Typically, reflection on the “political foundations” of international law has been undertaken in the introductory or “methodological” sections of standard treatises. These have had only marginal – if any – consequence on the doctrinal elaborations of different areas of international law. Lawyers seem to have despaired over seeing their specific methodology and subject-matter vanish altogether if popular calls for sociological or political analyses are taken seriously. Ultimately, they believe, there is room for a specifically “legal” discourse between the sociological and the political – a law “properly so called”, as Austin put it – and that this is the sphere in which lawyers must move if they wish to maintain their professional identity as something other than social or moral theorists.