According to Amrullah Saleh, Afghan State Minister for Security Reforms:
we are fighting a terrorist group sponsored and assisted by a nuclear state sitting next to us
Afghanistan has borders with two nuclear states, Pakistan & China.
A Guardian report from 2010 says:
At least 180 files contain allegations of dirty tricks by the powerful agency with accounts of undercover agents training suicide bombers, bundles of money slipping across the border and covert support for a range of sensational plots including the assassination of President Hamid Karzai, attacks on Nato warplanes and even poisoning western troops' beer supply.
They also link the ISI to some of the war's most notorious commanders. In April 2007 for instance, the ISI is alleged to have sent 1,000 motorbikes to the warlord Jalaluddin Haqqani for suicide attacks in Khost and Logar provinces.
But for all their eye-popping details, the intelligence files, which are mostly collated by junior officers relying on informants and Afghan officials, fail to provide a convincing smoking gun for ISI complicity. Most of the reports are vague, filled with incongruent detail, or crudely fabricated. The same characters – famous Taliban commanders, well-known ISI officials – and scenarios repeatedly pop up. And few of the events predicted in the reports subsequently occurred.
A retired senior American officer said ground-level reports were considered to be a mixture of "rumours, bullshit and second-hand information" and were weeded out as they passed up the chain of command. "As someone who had to sift through thousands of these reports, I can say that the chances of finding any real information are pretty slim," said the officer, who has years of experience in the region.
Is Pakistan or China funding and assisting terrorist insurgents in Afghanistan?