Polarization, foreign military intervention, and civil conflict

This paper tests whether foreign military intervention helps explain conflict by intensifying polarization. Building on the seminal papers of Montalvo and Reynal-Querol (2005) and Esteban and Ray (2011) and using a panel for 138 countries from 1960 to 2005, we confirm that ethnic polarization is a robust predictor of civil war. However, we also find that religious polarization is positively and significantly associated with civil conflict in the presence of foreign military intervention of non-humanitarian and non-neutral nature in the Middle East and North Africa, but not in the rest of the world. This type of intervention intensifies religious polarization through its effect on alienation, increasing the risk of high intensity conflict. The results provide an explanation for the high incidence of civil conflict in the Middle East and North Africa despite moderate polarization levels, obtained using the Reynal-Querol (2002) index, which is time-invariant and factors in only identity concerns.