Does Public Opinion Shape Elite Support for Defending Allies? Evidence on the Microfoundations of Collective Defense from the British Parliament

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

Abstract: Prominent theories of alliance politics rest on assumptions about the public’s role in shaping democratic states’ decisions to honor collective defense commitments. However, we still lack evidence on whether public and elite views on collective defense diverge and how voter preferences influence the decision-making of their elected representatives. To address this gap, we conducted a mixed-methods study in the United Kingdom, combining a paired pre-/post- intervention survey with members of the British Parliament (N = 100) and the British public (N = 1029), an elite survey of British parliamentarians with open-ended responses (N = 102), and in-depth semi-structured interviews with former and sitting British MPs (N = 13). We find substantial elite–public gaps, with parliamentarians more willing to defend a NATO ally under attack than the public. We also demonstrate that counter-attitudinal public cues shift elite preferences on defending allies, although the effect is substantively modest. Qualitative evidence suggests heterogeneity in elite approaches toward public opinion in defense issues and the latent nature of public influence: it can become politically consequential when military commitments are costly, sustained, morally salient, or linked to mobilized constituencies. Our findings provide important micro-level evidence on the public-elite linkage for scholarship on collective defense and allied solidarity, amid growing polarization and disinformation campaigns targeting NATO publics.

Keywords: military alliance, NATO, collective defense, public opinion, elite survey, elite experiment, mixed-methods, elite responsiveness, foreign policy