This paper investigates the effect of domestic power sharing between a government and its military on a state's propensity for international conflict. It uses a model of domestic political interactions in which the government and military have common interests in the state's security and conflicting interests over the distribution of domestic benefits. An activity available to the military may help or harm the state's security, and whether the expected outcome is positive or negative is known only to the military. The model shows that government steps to consolidate domestic power can lead the military to engage in activity that is more likely than not to harm the state's security, although, without the pressures of domestic politics, it would prefer to refrain from the activity. The paper thus elucidates a mechanism by which states with substantial domestic power sharing between governmental and military leaders have a greater propensity for international conflict.