We assumed that a breach in psychological contract had an effect on soldiers' well-being and not only promoted their burnout levels but decreased their levels of engagement. In a longitudinal study with 387 individuals on a peacekeeping mission, we analyzed the impact of the noncompliance of Army obligations in this mission on the burnout and engagement of soldiers. We found that during the mission their levels of burnout increased, whereas their engagement levels dropped. At the end of the mission, however, this breach in psychological contract did not influence their burnout levels, in spite of a continued reduction in the soldiers' engagement. Theoretical and practical implications are discussed and limitations and suggestions for future research are presented.