ISLAMABAD, Pakistan — They are dead men talking, and they know it. Gulping nervously, the prisoners stare into the video camera, spilling tales of intrigue, betrayal and paid espionage on behalf of the United States. Some speak in trembling voices, a glint of fear in their eyes. Others look resigned. All plead for their lives.

“I am a spy and I took part in four attacks,” said Sidinkay, a young tribesman who said he was paid $350 to help direct C.I.A. drones to their targets in Pakistan’s tribal belt. Sweat glistened on his forehead; he rocked nervously as he spoke. “Stay away from the Americans,” he said in an imploring voice. “Stay away from their dollars.”

Al Qaeda and the Taliban have few defenses against the American drones that endlessly prowl the skies over the bustling militant hubs of North and South Waziristan in northwestern Pakistan, along the Afghan border. C.I.A. missiles killed at least 246 people in 2012, most of them Islamist militants, according to watchdog groups that monitor the strikes. The dead included Abu Yahya al-Libi, the Qaeda ideologue and deputy leader.

Despite the technological superiority of their enemy, however, the militants do possess one powerful countermeasure.