FRONTLINE A rare and shocking look at how ISIS fighters are infiltrating some areas of Afghanistan and taking over every aspect of local life. They even run the local schools. Watch as children as young as three learn about machine guns, grenades and jihad. (Learn more: http://ift.tt/y7PjwC)

A rare and shocking look at how ISIS fighters are infiltrating some areas of Afghanistan and taking over every aspect of local life. They even run the local schools. Watch as children as young as three learn about machine guns, grenades and jihad. (Learn more: http://ift.tt/y7PjwC) FRONTLINE Are you ready for ISIS?