The Expansion of International Law Beyond Treaties

International law is going through a period of change and, potentially, expansion. At a point in history during the past millennium, the main sources of inter-State law were custom and general principles of law recognized by civilized nations. This came to an end with the Westphalian era when an international order slowly began to establish and a treaty system was developed. Thus, such international law sources as custom and general principles of law gave way to an era of treaties: Carefully designed instruments at the international level that codified every single aspect of agreements and transactions between nations. This phenomenon was not exclusive to the universal level; it also took place at a regional scale during the twentieth century, which saw the emergence of regional organizations and agreements that would enable the development of a reasonably stable international or regional society.