<p>How do core beliefs about right and wrong shape American attitudes about foreign policy? Political psychologists increasingly recognize that moral conviction constitutes an important and consequential dimension of attitude strength. Yet we know little about moral conviction beyond the water’s edge. We map moral conviction in the context of foreign policy and investigate its implications in two steps. First, we field an original survey and embedded experiments to investigate moral conviction in foreign policy at the issue, target, and individual levels. We find that foreign policy is neither amoral nor uniformly moralized; moral conviction varies. Foreign policy orientations provide domain-specific individual-level antecedents. However, the target state does not systematically affect policy moralization. A second survey then investigates the effects of moral conviction on cost tolerance and participatory actions. The results show that high costs decrease policy support. This effect weakens with moral conviction about vaccine aid, but not counter-terrorism operations. Taken as a whole, the project sheds light on the domain-specific characteristics of foreign policy attitudes and the role that moral conviction plays in building stable public coalitions of support for foreign policy decisions.</p>