How is subjective well being (SWB) of adolescents in boarding schools affected by threatened war, and related to perceived social support, self-control skills, and self-efficacy beliefs? Five hundred sixty-seven adolescents in five Israeli boarding schools completed questionnaires before the 2003 Iraq war. As expected, participants' fear of war affected SWB, and adolescents with high social support and self-control reported better SWB than low-scoring counterparts. Unexpectedly, self-efficacy regarding effective coping with upcoming war was unrelated to SWB. However, self-efficacy moderated links between social support and two SWB components (positive affect, life satisfaction). High-efficacy participants showed positive support–SWB correlations, whereas low-efficacy participants showed none. Findings highlighted personal resources as maintaining adolescents' SWB in boarding schools even under extreme stress.