Do Threats or Shaming Increase Public Support for Policy Concessions? Alliance Coercion and Burden-Sharing in NATO.

This article examines how American signals of support and threats of abandonment influence public support for increased defense spending among NATO allies, focusing on survey experiments conducted in Poland and Germany. The findings indicate that threats of abandonment—where the U.S. signals it may withhold defense if allies do not increase spending—significantly raise public support for higher military expenditures, especially when paired with assurances of protection, while normative appeals to shared obligations and "naming and shaming" under-contributing allies have little effect. Although threats can provoke anger and distrust, combining them with reassurances mitigates backlash and enhances effectiveness. These results contribute to understanding alliance burden-sharing dynamics, the role of coercion in international relations, and suggest that a balanced approach of conditional pressure may best encourage allied defense contributions.