With the notable exception of the Inter-American System very few regional groupings existed before World War II [6] What did emerge before World War II were a growing number of international public and private associations, such as the General Postal Union and the International Law Association, which were holding regular meetings and had their own secretariats.
By the 1940s however, an increasing number of influential people had already advocated "escape from a theoretical and ineffective universalism into practical and workable regionalism".
The treaty establishing the Benelux Customs Union was signed in 1944 by the governments in exile of Belgium, Netherlands and Luxembourg in London, and entered into force in 1947.
[9] The Nordic Council's statutes set out in the 1962 Helsinki Agreement, according to which the parties undertake "to seek to preserve and further develop co-operation between our nations in the legal, cultural and financial areas as well as in matters relating to transport and protection of the environment".
By the late 1950s, "the organization of the world's ninety-odd states into various systems of competing and overlapping regional associations [had been] a fact of international relations for over ten years".
Some critics were arguing that economic unions and common markets distorted the logic of a universal division of labor, and that regional military planning was made both impossible and obsolete.
[10] By the 1960s a number of important changes in international politics – the easing of the intensity of the Cold War, the independence of new states that had been part of colonial empires, the successful initiation of the European integration experience – gave rise to a new range of questions about regionalism.
According to Nye the new international environment made "the collective security and military defense focus of the writings in the early 1950s seem at best quaint and at worst misleading".
[11] The renewed academic interest in regionalism, the emergence of new regional formations and international trade agreements like the North American Free Trade Agreement (NAFTA), and the development of a European Single Market demonstrate the upgraded importance of a region-by-region basis political cooperation and economic competitiveness.
^ According to the article 33 of the Chapter VI of the UN Charter, regional bodies are regarded as agencies of the first resort in dealing with disputed among their own members.