Dialogue IO

Previously Published

Whence Causal Mechanisms? A Comment on Legro

Patrick Thaddeus Jackson  and Daniel Nexon 


In Whence “American Internationalism” Jeffrey W. Legro makes three important contributions to the study of international relations in general and to the development of constructivist theory in particular. First, Legro convincingly shows that the shift in American foreign policy from unilateralism to internationalism after World War II cannot be understood without reference to collective understandings about foreign policy. Second, he demonstrates that the interaction between prior intersubjective beliefs, external events, and heterodox views is an essential component of any study of ideational change. Third, Legro lucidly identifies a major problem in mainstream constructivist literature: how to theorize the translation between individual beliefs and cultural structures. This “collective ideation problem,” as Legro calls it, has undermined the explanatory force of normative, ideational, and identity-based explanations for some time.