Some excerpts, based on interviews with several Taliban and Haqqani commanders:
Support to the Afghan insurgency is official ISI policy. It appears to be carried out by both serving and former officers, who have considerable operational autonomy.
A number of analysts suggest that due to American and international pressure in 2006, 2007 or later, Pakistan has curtailed its support for the insurgents, but there is little evidence to support this.
Waldman summarizes that:
Pakistan appears to be playing a double-game of astonishing magnitude. The conflict has led to the deaths of over 1,000 American and 700 other foreign military personnel; thousands of Afghan soldiers, police, officials and civilians; and an unknown number of Afghan, Pakistani and other foreign insurgents. It has already cost America nearly $300 billion, and now costs over $70 billion a year. As a Haqqani commander put it: ‘Of course Pakistan is the main cause of the problems [in Afghanistan] but America is behind Pakistan.’
Why is Pakistan doing this? Their overriding concern is India.
As Steve Coll explains (The New Yorker, 1 March 2010): ‘Pakistan’s generals have retained a bedrock belief that, however unruly and distasteful Islamist militias such as the Taliban may be, they could yet be useful proxies to ward off a perceived existential threat from India. In the Army’s view, at least, that threat has not receded.’
So, what does Waldman conclude that the U.S. should do?
The priority must be to address the fundamental causes of Pakistan’s insecurity, in particular its latent and enduring conflict with India. This requires a regional peace process and, as Bruce Riedel has argued, American backing for moves towards a resolution of the Kashmir dispute.
So, in other words, if the Kashmir dispute is resolved, the Pakistan army will no longer see India as a threat, and they will then stop sponsoring terrorism? This conclusion sounds weak, because it is based on the assumption that the Pakistan army's hatred of India is a rational response to something India has done or not done.
But this hatred is not based on what India does or does not do. It is a self-sustaining mechanism of survival for the Pakistan military, whose enormous clout and influence within Pakistan depends on always having an external threat. Their hatred of India is institutionalized since the founding of Pakistan, and especially since Zia's Islamization.
And that is as clear as the Sun in the Sky.