The rule of law, in the sense in which it is used in this chapter, is a meta-legal principle concerned to constrain the way in which power can be exerted by power-holders. It is a quintessentially liberal doctrine grounded in the insights of English scholars such as Lord Acton and A.V. Dicey, as well as continental proponents of ideas such as the German concept of Rechtsstaat and the Russian notion of the pravovoe gosurdarstvo. Classical realist concepts of world politics, focussed on power and interests, did not leave much room for the rule of law in international relations, but two world wars, and the carnage associated with them, prompted shifts in thinking. As a political ideal, the international rule of law seemed worth trying, at least when measured against the consequences of the alternative. This chapter makes three seemingly trivial yet often overlooked points. The first is that the development of the mechanisms to give effect to the international rule of law can be a complex process in which norms and institutions take shape over a considerable period of time, and norms frame institutions that emerge to give them greater effect. The second is that even the development of norms and institutions does not guarantee that the desired outcome will eventuate. Law takes time to triumph over politics, and may take a very long time indeed. The particular example laid out in the chapter is that of the criminalization of aggression. The third point is that in its more complex manifestations, the crime of aggression is quite likely to continue to go unpunished. The chapter is divided into six sections. In the first, I clarify some key terms that figure in the discussion – convention, norm, institution – and outline some ways in which norms emerge to shape international politics. The second examines the 1928 Kellogg-Briand Pact as the mechanism through which the idea of a general prohibition of aggressive war surfaced. The third looks at the impact of the Charter of the United Nations, as well as the Nuremberg Trial of 1945-46 and the Tokyo Trial of 1946-48. The fourth discusses the emergence of the International Criminal Court, and the definition of aggression that was built into its Statute in 2010. The fifth examines Pakistani support for the Taliban as a problem which prime facie might attract attention as an example of aggression. In the light of this example, the sixth offers some brief conclusions, of which the most important is that, just as in domestic political contexts, considerations of
power may counterbalance the impetus to move towards a law-governed society of states with robust and effective enforcement mechanisms.