This dissertation examines the effect of wartime violence on individual preferences and behavior in the context of national security and foreign policy. The central theory proposes that exposure to wartime violence instills fear in both elites and the general public, leading to increased support for military armaments, particularly the development of nuclear weapons, as a means of safeguarding their respective nations from external aggression. This heightened fear also makes them hesitant to employ military force due to a profound understanding of the devastating consequences of war. The dissertation consists of three papers that examine this relationship at three distinct levels: the general public, national leaders, and legislators. The first paper demonstrates that individuals who were exposed to wartime violence during childhood exhibit increased support for nuclear proliferation. These individuals are more sensitive to security threats, leading them to place greater value on nuclear weapons as a deterrent against major invasions. This theory is empirically validated through a difference-in-differences analysis of the South Korean public. The second paper extends the analysis to the elite level, examining whether leaders' decisions to initiate conflicts are influenced by their childhood exposure to wartime violence. By using an original dataset, I compare leaders who experienced foreign military invasions during their child-hood, drawing on the variations in their personal traumatic experiences. The findings reveal that leaders who suffered family deaths, family injuries, or displacement due to war are less inclined to initiate militarized disputes compared to those who did not undergo such experiences. These effects are particularly pronounced when political constraints are weak. The final paper investigates the behavior of legislators with prior experiences of state repression and their propensity to criticize foreign political rights violations. These politicians empathize with foreign victims whose experiences resonate with their own, and they are driven by domestic political motivations to advocate for human rights. The theoretical argument finds support in the analysis of roll-call vote patterns within the South Korean legislature.
