Retrenchment Signaling and the Erosion of NATO Credibility under Trump 2.0

Michal Smetana, Lauren Sukin, Marek Vranka, Ondřej Rosendorf, Isabelle Haynes

Abstract: Has Trump’s confrontational stance toward U.S. allies undermined NATO’s credibility? To address this critical question, we conducted a large, survey-based longitudinal study investigating changes in perceptions of NATO’s collective defense commitments across selected allied states (the United States, the United Kingdom, Germany, Poland, and Canada), the Russian Federation, and in the British and German parliaments. In line with our theory of retrenchment signaling, we found a dramatic decline in the credibility of the U.S. commitments to NATO during the first year of Trump’s second administration (first-order effect), accompanied by a more modest increase in the credibility of non-U.S. allies (second-order effect). We demonstrate that the net impact on NATO’s overall credibility has been negative, showing asymmetric alliances suffer from a “substitution deficit” in credibility signaling. Furthermore, our investigation in Russia suggests that U.S. retrenchment signaling has even more negative consequences for allied deterrence than assurance due to the “strongest-link bias,” in which adversaries tend to overidentify the credibility of asymmetric alliances with that of their leading power. Finally, we show that political elites across allied states have been at least as skeptical about the U.S. commitment to defend its allies as the general population. Our longitudinal study provides the first systematic empirical evidence of the erosion of NATO’s credibility under “Trump 2.0” and contributes to scholarship on the dynamics of military alliances and the impact of great power retrenchment on world politics.

Keywords: Collective defense, Military alliance, NATO, Public opinion, Elite survey, Trump, Credibility