Can the Islamic State Defeat the Taliban?

After nearly 15 years of war, the Taliban are far from exhausted in their struggle for power. Against old enemies and new threats, the Taliban continue to maneuver for a better position in Afghanistan's conflict. While the Taliban are not capable of securing an outright victory against the Afghan government, the group is also unlikely to be sidelined, either by coalition efforts or by the entrance of a new rival for territory and influence: the Islamic State.