The enormous task of tracing scholarly work in a field of study as old as international law might at first give one reason to pause. Thankfully for this author, however, the distinction between legal and political issues in international law received little treatment prior to the latter half of the nineteenth century. It is about that time that states began to challenge one another in international tribunals, introducing into debate the question of which issues it could appropriately be said were subjects of third-party judgments, a debate willingly taken up by interested scholars and lawyers.
Even limiting one's examination to the latter half of the nineteenth century forward, however, is no small task. It requires some framework for manageably following the evolution of scholarly thought on the subject. One possibility is to view it on a time line. Interestingly enough, that time line may be broken up into three sections, these sections divided by the two world wars of the twentieth century: pre-World War I, interwar, and post-World War II.
The first differentiation between legal and non-legal issues in international law actually was made by Emmerich de Vattel in 1758, when he distinguished between two different types of rights. He does take positive note of arbitration, writing: "Arbitration is a very reasonable means, and one that is entirely in accord with the natural law, of terminating every dispute which does not directly affect the safety of the State."1 But then he immediately issues a caveat that states are not to entrust their survival to arbitral tribunals. There are two very different types of disputes in relations between states: "In the disputes which arise between sovereigns, a careful distinction must be made between essential rights and less important rights, and a different line of conduct is to be pursued accordingly."2
Pursuing different lines of conduct meant for Vattel that "essential rights" were not justiciable and "rights of lesser importance" were justiciable. Until the