This study evaluates the mental health of Japan Self-Defense Force (JSDF) members of the peacekeeping contingent in the Golan Heights before and since the Second Gulf War between 1998 and 2003. Before the war, the General Health Questionnaire 30 (GHQ30) scores during and after duty tended to be lower than those before duty; all scores were lower than those of adult Japanese men in general. After the war, GHQ30 scores did not significantly change between before, during, and after duty. Manifest Anxiety Scale (MAS) scores were not significantly different between groups. Stressors identified included problems with foreign language and familial matters at home. Post war stressors included work content and relationships with collaborating foreign army units. These findings suggest that the mental health of contingent members remained stable, with some variation in mental health conditions influenced by the situation in the Middle East. This study suggests that the stable mental condition of JSDF personnel during their deployment in the absence of combat, and that this could be enhanced by education about mental health issues and by providing counseling support to their families.