I study the relationship between the likelihood of a violent domestic conflict and the risk that such a conflict externalizes" (i.e. spreads to another country by becomingan international dispute). I consider a situation in which a domestic con ict between a government and a rebel group externalizes. I show that the risk of externalization increases the likelihood of a peaceful outcome, but only if the government is suficiently powerful relative to the rebels, and if the risk of externalization is suficiently high. I show how this model helps to understand the recent and successful peace process between the Colombian government and the country's most powerful rebel group, the FARC, that ended 52 years of armed conflict.
