about by the need for national security. Usually known as "federations" or "alliances," nation-states would integrate in order to fend off threats of conquest. The analysis of integration in these older times thus focused on constitutionalism. The grant of power to central authorities in a security alliance was seen as a measure of political consensus between the actors and was insufficient grounds for creating a permanent alliance, usually eroding once the immediate military threat subsided. The emphasis was on an analysis and description of the constitutions of nations in an alliance rather than non-legalistic forms of international cooperation.
Case studies have provided most of the raw material underlying integration theory. Karl Deutsch and Richard Van Wagenen offered one of the first pioneering studies in this field when they examined 10 cases of regional integration Deutsch and Wagenen, 1957). These cases ranged from the formation of England in the Middle Ages to the collapse of the alliance between Ireland and the United Kingdom in 1921. From these case studies, they derived a list of conditions necessary for both amalgamated and less monolithic security alliances.
Ernst Haas has carried the theory of integration a step further through comprehensive research of one international organization at a time. His research of the operations of the European Steel and Coal Community (Haas, 1958) and the International Labor Organization (Haas, 1964) has helped develop the concept of how the integration of one government function "spills over" into another area. This concept is largely derived from functionalist theory, discussed below.
The study of international integration has bearing on the role of international organizations in nurturing a world order and containing war. The work by Deutsch and Wagenen on pluralistic security alliances, for example, calls into question the traditional assumption that world order can only c...