While Snowden was holed up, an N.S.A. delegation, led by General Keith Alexander, and the then director of the Threat Operations Center, Rick Ledgett, boarded a military jet to Hawaii to try to make sense of Snowden and the damage he had caused. For months after Snowden revealed his identity, it was hard to find anyone at the N.S.A. who would utter his name in public. This was to some extent a denial reaction, reflecting shock and embarrassment. There was also a sense of personal betrayal, says Ledgett, who adds, “It was like getting kicked in the stomach.

“It’s the national-security implications, which are, you know, immense,” he continues. “And it’s somebody who had one of these badges,” he says, fingering his own top-security-clearance badge, “who betrayed the organization…. You like to think that you have shared values, and you have shared reasons for being here, because it’s not the pay. So to realize the organization is harboring this person, who didn’t share those views, and then betrayed us that way … ” His voice trails off.

He and Alexander talked to Snowden’s superiors and co-workers and “retraced his footsteps, saw what he did, saw where he sat,” says Ledgett. To assess the threat of more Snowdens, they had to understand what made people like him tick. What had driven this 29-year-old to give up almost everything he had ever known, possibly forever?

Snowden has insisted it was all about principles, about a lone individual standing up to fight. “You can get up every day,” he told The Guardian, “go to work, you can collect your large paycheck for relatively little work against the public interest, and go to sleep at night after watching your shows. But if you realize that is the world you helped to create, and it’s going to get worse by the next generation and the next generation . . . ”

In the intelligence community, however, there is a starkly different point of view. “Snowden to me is just like the spies in the Cold War who went to work for the Russians because they believed ideologically,” says a former senior intelligence official. “Manning is clearly troubled psychologically and emotionally, but with Snowden you seem to have a true believer,” he says, “driven by the proposition that all information should be free.”

In counter-espionage there is a template for evaluating the psychological motivations of those who are likely to spy, to become double agents. The acronym is MICE, which stands for money, ideology, compromise or coercion, and ego. After the early, ideological Americans who spied for the Soviet Union, things devolved, experts say, as spies increasingly did it for the money and for ego reasons. For many of those who consider Snowden a traitor, he scores high on the ego motive. They cite the swagger in his Internet postings, the braggadocio of his public statements, including his claim to The Guardian that he had the power to wiretap anyone, “even the President, if I had a personal email.” (“Bullshit,” says Ledgett.) In Snowden’s Ars Technica posts, the former official argues, “you don’t get any sense of a struggle, any inner debate, or conflict, or concern … I think he is a narcissist, a lot like Rick Ames” (the 90s-era C.I.A. turncoat).

What no one, not even Snowden’s most vociferous critics, suggests, though, is that Snowden did it for money or personal gain. “There are some whistle-blowers out there who do want to be deified,” says Jesselyn Radack, one of Snowden’s lawyers and the national-security-and-human-rights director at the Government Accountability Project, which advocates for whistle-blowers. But whistle-blowing, especially from within the intelligence world, where there is virtually no protection from whistle-blower laws, is too traumatic, Radack says, for anyone to do it lightly, or for ego gratification only. Radack was herself a whistle-blower—a former Justice Department attorney, she was pushed out of her job after objecting internally to the torture and interrogation of John Walker Lindh, the 20-year-old American who was captured fighting with the Taliban in 2001. She later leaked the information to Newsweek. In the process, Radack went “through hell,” as she puts it. No law firm would hire her; the government blackballed her privately and pursued her legally; she was ostracized. Among the many “smears that whistle-blowers are subjected to: that they did it for vengeance, fame, profit, or self-aggrandization. People try to pathologize whistle-blowers,” says Radack. Some might be naïve, others hopelessly idealistic or moralistic, or intense, but what all do, she says, is “underestimate the sheer force of the executive branch raining down on you.” And what all endure is a cavernous loneliness. “It’s this weird netherworld, very lonely and isolated,” she says. “And when you are charged with the Espionage Act”—as Snowden has been—“you are radioactive. You may as well be charged with being a pedophile cannibal.”

The Morning After

To this day, no one, maybe not even Snowden himself, really knows how many documents he took; estimates vary wildly. Snowden cautions about some of the numbers that investigators have publicized, especially the 1.7 million figure, which, he says, is “simply a scare number based on an intentionally crude metric: everything that I ever digitally interacted with in my career.” He adds, “Look at the language officials use in sworn testimony about these records: ‘could have,’ ‘may have,’ ‘potentially.’ They’re prevaricating. Every single one of those officials knows I don’t have 1.7 million files, but what are they going to say? What senior official is going to go in front of Congress and say, ‘We have no idea what he has, because the N.S.A.’s auditing of systems holding hundreds of millions of Americans’ data is so negligent that any high-school dropout can walk out the door with it’?”