Ahmed Rashid has a short review of the impact of ISIS in Afghanistan and Pakistan:http://www.nybooks.com/blogs/nyrblog...6/allure-isis/

He ends with:
If the war in Afghanistan drags on without a decisive victory or a political solution, the danger grows that younger Taliban will become more attracted to ISIS. And the possibility of ISIS wielding growing influence among the Pakistani or Afghan Taliban is heightened by the generational shift taking place among the Taliban themselves.

Unless Pakistan and Afghanistan are able to quickly end the extremism by Taliban groups that has plagued them for years they are likely to find themselves facing a far more militarized, radicalized, and extremist youth movement. The danger then is that these countries could find themselves ceding major territory to extremist groups, in a repeat of what ISIS has done in Iraq and Syria.