The strikes have cast a pall of fear over an area that was once a free zone for Al Qaeda and the Taliban, forcing militants to abandon satellite phones and large gatherings in favor of communicating by courier and moving stealthily in small groups, they said.
The drones, operated by the C.I.A., fly overhead sometimes four at a time, emitting a beelike hum virtually 24 hours a day, observing and tracking targets, then unleashing missiles on their quarry, they said.
The strikes have sharpened tensions between the local tribesmen and the militants, who have dumped bodies with signs accusing the victims of being American spies in Miram Shah, the main town in North Waziristan, they said.
The impact of the drone strikes on the militants’ operations — on freedom of movement, ability to communicate and the ease of importing new recruits to replace those who have been killed — has been difficult to divine because North Waziristan, at the nether reaches of the tribal area, is virtually sealed from the outside world.
None of those interviewed would allow their names to be used for fear for their safety, and all were interviewed separately in a city outside the tribal areas. The supporters of the government worked in positions where they had access to information about the effects of the drone campaign.
Along with that of the militant, the accounts provided a rare window on how the drones have transformed life for all in the region.