In his excellent book Sociologists, Economists and Democracy (1970), Brian Barry identified and analyzed two of the foremost approaches to theorizing in contemporary social science: the sociological and economic modes of theory construction. This study will draw on the insights provided by these two types of social theories in an attempt to understand international political change. Each type of social theory makes its own contribution. However, in this study we shall regard both as suggestive, rather than as methodologies to be applied rigorously. Thus their strengths and weaknesses will be discussed here briefly to familiarize the reader with the intellectual background and underlying methodology of this book.

The fundamental feature of sociological theory is its emphasis on whole societies or whole social systems. Although definitions of social systems vary, they have in common the notion of a set of identifiable elements characterized by explicit or implicit interrelationships. Whether these elements are individuals, groups, social roles, or other factors, sociological theory assumes that individual behavior is explained by the nature of the system and one's place in it. The social system is the primary determinant of behavior, either by socializing the actor with respect to a particular set of norms and values or by exercising constraints on the actor. In brief, the whole is greater than the sum of its parts, and the social system itself must be the focus of theorizing.

In contrast to the holistic approach of sociological theory, economic theory, or what some call rational-choice theory, focuses on the individual (Becker, 1976, p. 5; Rogowski, 1978).