Mechanisms and microfoundations in International Relations theory

This article looks at prospects for a mechanism-based research strategy in the study of International Relations. Over the past three decades, the notions of mechanism and microfoundation have taken a central place in discussions of explanation and ‘micro-macro’ problems in social science. The upshot of much of this discussion has been a call for mechanism-based explanations – explanations of macro-level phenomena in terms of micro-level mechanisms. Some work of this kind can already be found in IR theory, including in systemic research. However, a number of IR theorists, including Kenneth Waltz and Alexander Wendt, have argued that micro-oriented strategies like this will not work, pointing to incongruities between system- and unit-level phenomena. This article argues that these pose less hindrance to a fully-developed model of mechanism-based explanation, and that the field has much to gain from further exploration of this strategy. In particular, mechanism-based explanations could help bring structure back to the centre of discussion in IR theory, and might even give us a way out of the field's own micro-macro problems.