The Power to Hurt and Public Support for War

How do changes in the “power to hurt” an adversary affect patterns of public support for war? Although the ability to inflict punishment is central to theories of coercive bargaining and war termination, current research on public opinion has thus far primarily focused on voters’ responses to friendly casualties—to their ability to withstand pain. The problem with omitting the power to hurt is that imposed costs are likely to drive patterns of public support for war. Increases in the power to hurt may increase support despite high friendly casualties. In contrast, decreases in the power to hurt may reduce public support even in situations with few friendly casualties. We fielded a novel survey experiment (pre-registered, N = 5337) that described a plausible conflict over Taiwan between the U.S. and China. We find that individuals intuitively understand the power to hurt as support for continued military action increases with the number of enemy casualties and decreases as the power to hurt weakens. Additionally, we explore three possible causal pathways—whether individuals 1) believe the U.S. has a moral duty to defend Taiwan, 2) understand battlefield performance as a signal for the probability of victory, and 3) perceptions of Chinese resolve—that could account for this dynamic. Finally, we also discuss a variety of pre-treatment moderators, including moral foundations regarding harm and loyalty, militant assertiveness, and nationalism and their impact on the effect of the power to hurt.