...But the Kandahar prisoners were not playing by the army rule book. They divulged nothing. “Prisoners overcame the [traditional] model almost effortlessly,” writes Chris Mackey in The Interrogators, his gripping account of his interrogation service in Afghanistan. The prisoners confounded their captors “not with clever cover stories but with simple refusal to cooperate. They offered lame stories, pretended not to remember even the most basic of details, and then waited for consequences that never really came.”

Some of the al-Qaida fighters had received resistance training, which taught that Americans were strictly limited in how they could question prisoners. Failure to cooperate, the al-Qaida manuals revealed, carried no penalties and certainly no risk of torture—a sign, gloated the manuals, of American weakness.

Even if a prisoner had not previously studied American detention policies before arriving at Kandahar, he soon figured them out. “It became very clear very early on to the detainees that the Americans were just going to have them sit there,” recalls interrogator Joe Martin (a pseudonym). “They realized: ‘The Americans will give us our Holy Book, they’ll draw lines on the floor showing us where to pray, we’ll get three meals a day with fresh fruit, do Jazzercise with the guards, . . . we can wait them out.’ ”

Even more challenging was that these detainees bore little resemblance to traditional prisoners of war. The army’s interrogation manual presumed adversaries who were essentially the mirror image of their captors, motivated by emotions that all soldiers share. A senior intelligence official who debriefed prisoners in the 1989 U.S. operation in Panama contrasts the battlefield then and now: “There were no martyrs down there, believe me,” he chuckles. “The Panamanian forces were more understandable people for us. Interrogation was pretty straightforward: ‘Love of Family’ [an army-manual approach, promising, say, contact with wife or children in exchange for cooperation] or, ‘Here’s how you get out of here as fast as you can.’ ”

“Love of family” often had little purchase among the terrorists, however—as did love of life. “The jihadists would tell you, ‘I’ve divorced this life, I don’t care about my family,’ ” recalls an interrogator at Guantánamo. “You couldn’t shame them.” The fierce hatred that the captives bore their captors heightened their resistance. The U.S. ambassador to Pakistan reported in January 2002 that prisoners in Kandahar would “shout epithets at their captors, including threats against the female relatives of the soldiers guarding them, knee marines in the groin, and say that they will escape and kill ‘more Americans and Jews.’ ” Such animosity continued in Guantánamo...