Once renowned for its political cohesion, the Afghan Taliban movement now finds itself enduring sustained internal divisions and threats from rival factions. The revelation in July 2015 that the leader of the Taliban, Mullah Omar, had, in fact, been dead for nearly two years led to an internal power struggle that further fractured the Taliban movement. Ever since, various factions of Taliban fighters opposed to the current Taliban leadership council have engaged in open combat with their former group. The emergence of the Islamic State in Khorasan Province, a group that includes some disaffected Afghan Taliban commanders, has resulted in conflict between the two groups. The Afghan Taliban remains the most organized and lethal insurgent group operating in Afghanistan, and it controls significant swaths of the country. But its fracturing is weakening its ability to sustain its current position.