Pakistan has been unable to interdict prior terror attacks from bases inside Pakistan, of which the most notable was the Mumbai massacre. Since Muhammad Zia-ul-Haq’s Islamization, Pakistan has been hostage to the Kashmir issue not simply in a national sense, but from the control of an Islamic “infra-state”, continually reinforced by the human output of the madrassas.
On two occasions, Pakistan’s military has been able to reclaim areas from this infra-state, in the Swat Valley, and in the canyon suburbs of Karachi. But even though the ISI is said to favor better relations with India, the Kashmir attack could not be interdicted. Part of this is due to geography; the further out from the political center of the country (even 60 miles!), the lower the ratio of civil to Islamist influence. Pakistan is a very inconvenient country.
The current prime minister of Pakistan, Imran Khan has been described as lacking political conviction. His political coalition is broad but not deep. The ability of Pakistan’s civil government to confront the Islamist infra-state has always been weak. But Khan’s stated goal, to revive the Pakistan of founder Muhammad Ali Jinnah, implicitly reversing Zia-ul-Haq’s Islamization, makes him especially vulnerable.
The details of why the ISI could or would not close the terror bases, inspite of professed desire for better relations with India, are elusive to open source. This is, after all, the country that sheltered Osama Bin-Laden. Those responsible have never been identified.
The mysteries may be related.