Divisions at Home, Broken Promises Abroad? How Domestic Politics Shapes the United States’ Nuclear Credibility

Abstract How will the intensifying political challenges in the United States affect Washington’s nuclear credibility? Although the implications of US domestic politics often extend past American borders, few studies examine how foreign publics assess the US political environment. In the nuclear security domain, where the United States must maintain challenging extended deterrence commitments, domestic political conditions have especially destabilizing potential. Drawing on a novel, cross-national survey experiment, we test how four defining characteristics of US policymaking—political party, presidential ideology, polarization, and divided government—affect foreign publics’ evaluations of US nuclear credibility. We find little evidence that party stereotypes meaningfully inform such perceptions, but other political characteristics—particularly polarization—affect favorability toward the US government and decrease confidence in US deterrence. This could pose significant risks to the United States’ international standing in the security domain, which could persist even when party control changes.