Provocation, Intimidation and Nuclear Threats

• In Event: Nuclear Weapons and Military Alliances

Abstract

Can nuclear threats overcome the backlash that undermines other threats? While no one has used nuclear weapons since 1945, leaders often make nuclear threats, perhaps to ensure that their threats do not provoke push-back. Threats often provoke increased public support for crisis interventions, but nuclear threats may raise enough risks to intimidate as their users intend. The threshold where provocation turns to intimidation is unclear, however. I therefore test whether nuclear threats offset backlash with a survey experiment on the U.S. and German public and an analysis of how Vladimir Putin's February 27, 2022 nuclear alert impacted U.S. and German public support for engagement in Ukraine. These tests have complementary strengths and weaknesses, as the observational analysis may have greater external validity, while the experiment has greater internal validity and allows me to assess mechanisms. I find that nuclear threats rarely attenuate backlash. Threats are most likely to diminish backlash when other actions also raise escalation risks and the target is not a nuclear state. Nuclear signals can also backfire, as using demonstration explosions to underline a threat often increases backlash.

Author

• Joshua Alley, University College Dublin