After World War II, one of the most significant events in international relations was the founding of the United Nations. In the wake of the decolonization process came up a large number of newly independent States that drastically changed the composition of the international community. It is no surprise that Afro-Asian nations did not seek to re-establish their own traditional regional systems after attaining independence, but accepted the basic structure of the international society including international law, which Europeans had created, because most of their economies were still under the control of the western powers, whose recognition was crucial for these newly independent States to participate in world affairs. Whether and to what extent these States should succeed the international obligations that were passed on to them from colonial times constituted a long, hard political and legal struggle between the former colonial countries and the new States, during the course of which the traditional international law was constantly subject to critical review and revision. Although the political independence of these new States proved to be just the first step for them to effectively participate in international affairs, their presence on the world stage has nevertheless exerted a great impact on the facets of international relations and the formation of international law, as was to be witnessed by history.

Great changes took place not only in the composition of the international legal community after WWII, but more so in the contents of its law. Professor Bin Cheng attributes this to three aspects: codification and progressive development of interna­tional law by means of multilateral conventions, growth of international organizations and judicial developments. More important in substance is that fundamental principles of international relations were hardened into positive legal rules as enunciated in the purposes and principles of the UN Charter, the Declaration on Principles of International Law concerning Friendly Relations and Cooperation among States in accordance with the Charter of the United Nations, and the Charter of Economic Rights and Duties of States. Besides, in fighting against colonialism, apartheid, racial discrimination, States, old and new, generally accepted such principles as self-determination, protection of fundamental freedom and human rights, together with other basic principles, as peremptory norms of international law. In recognizing the underlying values of these basic principles by all States, the moral ground of the legal system was expanded beyond the traditional Christian morality and European politics and gradually shared by all forms of civilization across the world. This substantial change in the character of the law thus rendered a sound and truly universal basis to the international legal system.

Indisputably, international norms can never be separated from international reality. On the contrary, they must reflect it. At the same time, it is also generally realized that in international relations, asymmetry of power is an undeniable factor. The postulate of sovereign equality is often tested and squarely challenged by the factual inequality of States in practice. In spite of the positive changes mentioned above, the cold war era still saw that great powers and powerful groups continued to play a crucial role in the international law-making, and largely dictated its course, both within and outside the UN system. With two superpowers in rivalry, balance of power not only checked against any possible unilateral actions to be taken by one power to the detriment of the other, but also restrained the desirable progress of international law in the common interests of States at large, as international cooperation often became impossible when the two superpowers were in confrontation. The end of the cold war exerted a tremendous impact on the formation and progress of international law.

Apart from a fast proliferation of international conventions in the economic, social and environmental fields in the 1990s, international organizations, with the United Nations in particular, have become increasingly active and important in world affairs, and in the field of international law. Together with that change is the growing participation of NGOs in the international negotiation process. Communal interests in world security, human rights protection, development and environment have become identifiable and universal. Noticeably, acceptance of “civil society” on the interna­tional plane is not simply regarded as recognition of NGOs’ role, but more deeply, a direct interplay of public opinion on international law-making at domestic and international levels.

It would not be accurate to say that all the changes in the post-cold-war era are encouraging. With economic globalization and fragmentation of international law, such issues as poverty alleviation, development aid, and technical assistance, which are particularly significant to the developing countries, have been greatly margina­lized. For example, in 2002, while the budget for the International Criminal Tribunal for the Former Yugoslavia constituted about 10% of the UN total budget, official development aid to the developing countries dropped to less than 1%. If the legitimate concerns of the developing countries continue to be neglected or ignored, the very foundation of the world order, upon which the international community claims itself, would surely be questioned and weakened.