How Do Foreign Alliances Affect Civil War Onset?

Abstract

Treated as a practical approach to deterrence, foreign alliances are believed to have a tight relationship with the onset of interstate wars. Scholars have paid substantial attention to how foreign alliances affect international security, and how domestic alliances affect domestic security. However, there could be an interaction between elements from interstate and intrastate stages, and we still lack knowledge of the mechanisms and effects. I argue in this paper that, a state can deter the rebel groups within its ally’s territory, thus decreasing the probability of civil war onset of that ally. Like nation-states, rebel groups will also assess the allies’ capability and credibility of the state they fight against to decide whether they will initiate a civil war. However, neither capability nor credibility alone can explain this dynamic. Instead, they amplify each other to prevent the onset of civil war. I find that both capability and credibility have the effect of reducing civil wars, but their effects are strong enough only when the other variable is at its higher value.