A compound might contain dozens of houses, but if only one is used for training, it's difficult to know that, he says. "The drone attacks can only get at those targets for which one has very credible and actionable intelligence."
A range of camps
Camps cropped up across the country during the 1980s, when Pakistan and the United States funded the training of jihadis to send to Afghanistan to fight the Soviet occupation. Some of that physical infrastructure remains, but Dr. Hussein says not much would be useful since those camps were not designed for secrecy.
Their real legacy would be the military training and the Islamist mind-set that was passed down. After the Soviets withdrew, Pakistani intelligence elements continued to support Islamist militants both in Afghanistan – groups such as Mullah Omar's Taliban and Gulbuddin Hekmatyar's Hizb-e-Islami – and in Kashmir against India, through groups such as Lashkar-e-Taiba and Jaish-e-Mohammed. Some international jihadis also stayed on, forming Al Qaeda and attracting educated recruits with technical skills.