Disenchanted extremists from the Taliban and other organizations, impressed by the Islamic State group's territorial gains and slick online propaganda, have begun raising its black flag in extremist-dominated areas of both countries.
In Pakistan, an online video purportedly shows militants beheading a man while pledging their allegiance to the IS. In Afghanistan, there have even been reports of militant rivalries, with clashes erupting between Taliban fighters and Islamic State militants.
However, the rise of even a small Islamic State affiliate could further destabilize the region and complicate US and NATO efforts to end the 13-year Afghan war.
The Taliban remain the region's pre-eminent insurgency, with nearly 20 years of experience battling Afghan warlords and international troops. But the Taliban are "not a particularly sexy ideology or military force, and the risk lies in the Taliban looking increasingly out of date," said a Western diplomat, speaking on condition of anonymity to discuss intelligence matters.
The Islamic State group controls a third of both Syria and Iraq, where it declared a caliphate governed by a harsh interpretation of Islamic law, or Sharia, and demanded the allegiance of the world's Muslims. The Taliban, by contrast, are focused on Afghanistan and Pakistan, and some leaders have even responded to past peace overtures.
In Afghanistan's southern Helmand province, residents say a former Taliban commander named Mullah Abdul Rauf has begun recruiting fighters for the Islamic State group.
