Replication Data for: Do External Threats Unite or Divide? Security Crises, Rivalries, and Polarization in American Foreign Policy

A common explanation for increasing polarization in contemporary American foreign policy is the absence of external threat. I identify two mechanisms through which threats could reduce polarization: by revealing information about an adversary that elicits a bipartisan response from policymakers (information mechanism) and by heightening the salience of national relative to partisan identity (identity mechanism). To evaluate the information mechanism, Study 1 uses computational text analysis of the Congressional Record to explore whether security threats reduce partisanship in attitudes towards foreign adversaries. To evaluate the identity mechanism, Study 2 uses historic public opinion polls to assess whether threats reduce affective polarization among the public. Study 3 tests both mechanisms in a survey experiment that heightens a security threat from China. The studies show that the external threat hypothesis has limited ability to explain either polarization in U.S. foreign policy or affective polarization among American public. Instead, responses to external threats reflect the domestic political environment in which they are introduced. The findings cast doubt on predictions that new foreign threats will inherently create partisan unity.