The practice of international law
This chapter designates the analytical framework within which one can assess whether states, through their practice, recognize a rule, principle or practice as binding on them as law. Academic international lawyers do not usually go further in defining the practice of states than to look at the jurisprudence of the International Court of Justice on the issue of definition of customary international law, and, additionally, compiling official state communiqués in semi-official national yearbooks. We offer, instead, an explanation of how the archival tools of diplomatic history can reveal how far it is possible to construct an historical narrative that determines precisely whether law has formed part of the motivational structure of a state, when the question is whether it is observing or creating international law. At the same time, it is necessary, in expositions of state practice, to be aware, at the systematic, theoretical level, of the impact which the nature of international society will have on the willingness of states to give a place to international law alongside their anxieties about national interests and security. It is also valuable to consider not only the extent to which diplomatic history can make transparent the role of international law in state practice, but also the extent to which this practice does or does not confirm or deny the skepticism of realist theory about the place of international law in international society.