Isis will have a hard time getting a real foothold in Afghanistan because the taliban are pashtun nationalist something that isis thinks makes you a apostate, and pashtun nationalism is huge in Afghanistan
ISIS just assassinated the main Taliban leader
It remains to be seen what sheer brutalism wrapped in the sternest possible form of sharia will do to Afghanistan
Remember that Osama Bin Laden and al Qaeda flourished in Afghanistan and they were not pashtun