Author Mark Mazzetti tells Terry Gross about the primary focus of Pakistan’s military:
[A]s much as Pakistan has said and has told the United States, ‘Yes, we understand the problem in the tribal areas, the problem with al-Qaida, the problem with the Taliban. We will help in your war,’ fundamentally, at the end of the day, Pakistan worries about India and India worries about Pakistan and Pakistan and the Pakistani military is built to fight India. And so the money that they have accumulated and amassed from the United States over the years — I’m not saying it’s all being secretly diverted to buy F-16s to fight India — but certainly there has been a good deal of that money has been used to bolster Pakistan’s military that can then be used to go after what Pakistanis see as the main enemy.
Image of a Pakistan Army Exercise by zahidpix

