In order to explain why reluctance occurs, this chapter develops a theorization of reluctance in world politics. The conceptual discussion in Chapter 2 forms the basis of such theorization: as Goertz (2006: 5) argues in his seminal work, concept building is always strongly connected with theorizing because all social science concepts always inherently entail a causal dimension. In this chapter, I will therefore proceed by building on the two constitutive dimensions of reluctance – hesitation and recalcitrance – to develop a theoretical framework that helps explain why reluctance occurs in some cases but not in others, and why it occurs to different degrees. At the core of this theoretical framework is the very notion of foreign policy as a field that brings together domestic and international factors: on the one hand, foreign policies are clearly the result of a domestic process through which a range of actors within society aim to influence the government's approach to international affairs, and a number of domestic actors and institutions interact to reach foreign policy decisions. On the other hand, a country's foreign policy is always embedded in an international context, and subject to a range of constraints and expectations articulated by other actors.

This interplay of domestic and international factors will be the overarching framework to explain variations in the occurrence of reluctance. Those factors are clearly related to the two constitutive dimensions of reluctance: hesitation (with its elements of indecisiveness, flip-flopping and delaying) can be analysed in relation to domestic factors, and more specifically to the domestic process of preference formation, which can make it particularly difficult for a government to pursue a consistent and determined foreign policy (Destradi, 2018: 2224–5). As we will see, these difficulties in domestic preference formation can emerge for several reasons (political weakness, limited capacity, cognitive problems or normative struggles). Recalcitrance, which by definition refers to the idea of not conforming to others’ expectations, is related to international factors, specifically to the expectations raised by international actors (Destradi, 2018: 2224–5). As we will see, these domestic and international explanatory factors are deeply interrelated.

The following sections will build on a diverse set of literatures from various theoretical traditions of International Relations (IR), Foreign Policy Analysis (FPA), Social Psychology and Psychology, to detail how different kinds of difficulties in domestic preference formation and competing international expectations will lead to reluctance.