AP Photo

This security vacuum in the Aleppo region appears to have helped Jabhat al-Nusra, which is allied with al-Qaeda. The group is benefiting not just from its prowess on the battlefield but from its refusal to engage in looting and other predatory behavior. In its emphasis on crude but egalitarian justice and social services, Jabhat al-Nusra emulates other successful Muslim extremist organizations, such as Hezbollah in Lebanon and the Taliban in Afghanistan.