In international relations, regionalism is the expression of a common sense of identity and purpose combined with the creation and implementation of institutions that express a particular identity and shape collective action within a geographical region. Regionalism is one of the three constituents of the international commercial system (along with multilateralism and unilateralism).
The first coherent regional initiatives began in the 1950s and 1960s, but they accomplished little, except in Western Europe with the establishment of the European Community. Some analysts call these initiatives "old regionalism". In the late 1980s, a new bout of regional integration (also called "new regionalism") began and continues still . A new wave of political initiatives prompting regional integration took place worldwide during the last two decades. Regional and bilateral trade deals have also mushroomed after the failure of the Doha round .
The European Union can be classified as a result of regionalism. The idea that lies behind this increased regional identity is that as a region becomes more economically integrated, it will necessarily become politically integrated as well. The European example is especially valid in this light, as the European Union as a political body grew out of more than 40 years of economic integration within Europe. The precursor to the EU, the European Economic Community (EEC) was entirely an economic entity.
Joseph Nye defined an international region "as a limited number of states linked by a geographical relationship and by a degree of mutual interdependence", and (international) regionalism as "the formation of interstate associations or groupings on the basis of regions". This definition, however, was never unanimously accepted, and some analysts noted, for example, that the plethora of regional organizations founded at the initiative of developing countries had not fostered the rapid growth of regionalism in the Third World. Other authors, such as Ernst B. Haas, stressed the need to distinguish the notions of regional cooperation, regional system, regional organization and regional integration and regionalism.