ABSTRACT
When The Environment and International Relations was published in 1996, the dominant IR approaches were neorealism and neoliberal institutionalism. The unitary actor assumption on which the two theories are based was motivated by a preference towards parsimony. The aim of theory for those scholars was not to create an accurate representation of reality, but to abstract as much as possible while retaining explanatory and predictive power. Dissatisfaction with the prioritisation of systemic level explanations in structural approaches has created a large body of work on the interaction between domestic and international levels. Neoclassical realism is an attempt to think more systematically about how the domestic and international levels connect in foreign policy decision-making from a realist perspective. Liberalism does not accept the unitary actor assumption made by structural approaches, instead considering the main subjects of international relations to be individuals and groups. The attention given to the domestic–international politics interface in IR has expanded significantly in the past 20 years.
