A study by the Bureau of Investigative Journalism estimates that since 2004, Pakistan has had 365 drone strikes that have killed between 2,536 and 3,577 people -- including 411 to 884 civilians.
The study concludes that the strikes have killed far more people than the United States has acknowledged, and traumatized many more innocent people.
That trauma is destroying a way of life, Emmerson said. "The Pashtun tribes of the ... area have suffered enormously under the drone campaign."
And tribal law prescribes revenge for the killing of a tribe member, which serves to radicalize more young men against the United States, he said.
Pakistan considers the strikes counterproductive, illegal and a violation of its sovereignty.