Public attitudes toward nuclear weapons remain a critical issue in international security, yet the thinking behind individuals’ support or opposition to their use is not well understood. This study examines how the American public reasons about whether to deploy nuclear weapons in a hypothetical war between the United States and Iran. Participants were asked to state their preference between continuing a ground war, deploying a nuclear strike resulting in 100,000 civilian casualties, or deploying a strike killing 2 million civilians. They then provided an open-ended answer where they described the reasons for their decision. Using Structural Topic Modeling, we identified 10 distinct patterns in participants’ thinking. Some responses emphasized concerns about deterrence or saving lives, while others focused on national security, or retaliation, among other reasons. The type of thinking participants employed was found to be related to their preceding choice, as well as to individual characteristics, such as gender, political affiliation, punitive–authoritarian–nationalist attitudes, and the influence of the relative emotional impact of the 2 bombs (i.e., the better bomb effect). These findings highlight the complexity of the thinking underlying nuclear decision making and help shed light on potential avenues for reducing the risk of a nuclear weapon being deployed again.
