Article states: “The Indian concern is that Nangarhar province sits on the mouth of the Khyber pass, which has been the route to enter into the Indus Valley and the Gangetic plains,” explained one senior official. “Also, Farah province shares borders with Shia Iran. If IS manages to spread in Afghanistan, Pakistan and Central Asia, then India faces a serious security threat.”
http://www.breitbart.com/national-security/2015/07/05/isis-in-india-officials-concerned-terrorist-group-will-spread-out-of-pakistan/