Russia’s recent intervention in Syria will generate more opportunities for the Islamic State than it quells. If the Islamic State’s core defenses around major cities in Iraq and Syria hold, the Islamic State will weather Russia’s intervention and likely emerge stronger. The Islamic State has an effective defensive strategy, which it employed in the summer and early autumn of 2015. Apart from failing to compromise the Islamic State’s defenses, the Russian intervention will fracture the U.S.-led coalition and weaken Syrian rebel groups, giving the Islamic State freedom of action on fronts where it had been constrained previously. Committed opponents of the Islamic State still have opportunities to block and fix the group’s forces on multiple fronts, but these efforts will fail if a successful ground counter offensive does not free the Euphrates valley and Mosul from the Islamic State’s control. Russia’s attempts to remove the United States from Iraq and Syria will significantly degrade the formulation of such a ground strategy, and the Islamic State will benefit.