A common sense approach to analysing the cause of a specific foreign policy often refers to the motives, beliefs system or worldview of the actor. Theoretical frameworks developed over the last few decades, however, have moved away from grasping the issue from within: realism and structurism stress national interests and the limited room for policy choice that is imposed upon a state by the international system; behaviourism, the more scientific study of international relations (IR), leads to the de-composition of the unitary state (Waever 1990: 335). Foreign policy analysis (FPA), developed mainly in the USA since the 1950s, has engaged with rational-teleological explanations by reference to roles, individuals and institutions, as well as causal explanations in terms of development or political adaptation (see, for example, George 1969; Rosenau 1981). Since the 1990s, ideational factors have returned to FPA, aiming to reveal the mechanisms or the psychology that is internal to the cognitive sphere. Several frameworks have dealt with beliefs system, cognitive mapping and information processing (Khong 1992; Goldstein and Keohane 1993). In the existing IR literature on ideas, nevertheless, the ideas-policy linkage

has always been assumed and sometimes empirically demonstrated but seldom made explicit, still less been convincingly defined in theoretical terms.1

The lack of theoretical grounding for the ideas-policy linkage has been a major target for positivist IR theorists who attack constructivist theorizing for its lack of rigour and precision.2 This chapter constructs a theoretical framework that gives ideas a primary role in causal explanation in IR. It seeks to synthesize realist and liberal IR theories, and defines the theoretical, methodological and empirical domain in a ‘fruitful’, and not merely ‘traditional’, manner (Galtung 1967: 37).3