In the first in-person interview Edward Snowden has conducted since his arrival in Moscow in June, Barton Gellman reports:

“For me, in terms of personal satisfaction, the mission’s already accomplished,” he said. “I already won. As soon as the journalists were able to work, everything that I had been trying to do was validated. Because, remember, I didn’t want to change society. I wanted to give society a chance to determine if it should change itself.”

“All I wanted was for the public to be able to have a say in how they are governed,” he said. “That is a milestone we left a long time ago. Right now, all we are looking at are stretch goals.”

Snowden is an orderly thinker, with an engineer’s approach to problem-solving. He had come to believe that a dangerous machine of mass surveillance was growing unchecked. Closed-door oversight by Congress and the Foreign Intelligence Surveillance Court was a “graveyard of judgment,” he said, manipulated by the agency it was supposed to keep in check. Classification rules erected walls to prevent public debate.

Toppling those walls would be a spectacular act of transgression against the norms that prevailed inside them. Someone would have to bypass security, extract the secrets, make undetected contact with journalists and provide them with enough proof to tell the stories.

The NSA’s business is “information dominance,” the use of other people’s secrets to shape events. At 29, Snowden upended the agency on its own turf.

“You recognize that you’re going in blind, that there’s no model,” Snowden said, acknowledging that he had no way to know whether the public would share his views.

“But when you weigh that against the alternative, which is not to act,” he said, “you realize that some analysis is better than no analysis. Because even if your analysis proves to be wrong, the marketplace of ideas will bear that out. If you look at it from an engineering perspective, an iterative perspective, it’s clear that you have to try something rather than do nothing.”

By his own terms, Snowden succeeded beyond plausible ambition. The NSA, accustomed to watching without being watched, faces scrutiny it has not endured since the 1970s, or perhaps ever.

In the first in-person interview Edward Snowden has conducted since his arrival in Moscow in June, Barton Gellman reports:

The documents leaked by Snowden compelled attention because they revealed to Americans a history they did not know they had.

Internal briefing documents reveled in the “Golden Age of Electronic Surveillance.” Brawny cover names such as MUSCULAR, TUMULT and TURMOIL boasted of the agency’s prowess.

With assistance from private communications firms, the NSA had learned to capture enormous flows of data at the speed of light from fiber-optic cables that carried Internet and telephone traffic over continents and under seas. According to one document in Snowden’s cache, the agency’s Special Source Operations group, which as early as 2006 was said to be ingesting “one Library of Congress every 14.4 seconds,” had an official seal that might have been parody: an eagle with all the world’s cables in its grasp.

Each year, NSA systems collected hundreds of millions of e-mail address books, hundreds of billions of cellphone location records and trillions of domestic call logs.

Most of that data, by definition and intent, belonged to ordinary people suspected of nothing. But vast new storage capacity and processing tools enabled the NSA to use the information to map human relationships on a planetary scale. Only this way, its leadership believed, could the NSA reach beyond its universe of known intelligence targets.

In the view of the NSA, signals intelligence, or electronic eavesdropping, was a matter of life and death, “without which America would cease to exist as we know it,” according to an internal presentation in the first week of October 2001 as the agency ramped up its response to the al-Qaeda attacks on the World Trade Center and the Pentagon.

With stakes such as those, there was no capability the NSA believed it should leave on the table. The agency followed orders from President George W. Bush to begin domestic collection without authority from Congress and the courts. When the NSA won those authorities later, some of them under secret interpretations of laws passed by Congress between 2007 and 2012, the Obama administration went further still.

Using PRISM, the cover name for collection of user data from Google, Yahoo, Microsoft, Apple and five other U.S.-based companies, the NSA could obtain all communications to or from any specified target. The companies had no choice but to comply with the government’s request for data.

But the NSA could not use PRISM, which was overseen once a year by the surveillance court, for the collection of virtually all data handled by those companies. To widen its access, it teamed up with its British counterpart, Government Communications Headquarters, or GCHQ, to break into the private fiber-optic links that connected Google and Yahoo data centers around the world.

That operation, which used the cover name MUSCULAR, tapped into U.S. company data from outside U.S. territory. The NSA, therefore, believed it did not need permission from Congress or judicial oversight. Data from hundreds of millions of U.S. accounts flowed over those Google and Yahoo links, but classified rules allowed the NSA to presume that data ingested overseas belonged to foreigners.

Disclosure of the MUSCULAR project enraged and galvanized U.S. technology executives. They believed the NSA had lawful access to their front doors — and had broken down the back doors anyway.

Microsoft general counsel Brad Smith took to his company’s blog and called the NSA an “advanced persistent threat” — the worst of all fighting words in U.S. cybersecurity circles, generally reserved for Chinese state-sponsored hackers and sophisticated criminal enterprises.

In the first in-person interview Edward Snowden has conducted since his arrival in Moscow in June, Barton Gellman reports:

Snowden likened the NSA’s powers to those used by British authorities in Colonial America, when “general warrants” allowed for anyone to be searched. The FISA court, Snowden said, “is authorizing general warrants for the entire country’s metadata.”

“The last time that happened, we fought a war over it,” he said.

Technology, of course, has enabled a great deal of consumer surveillance by private companies, as well. The difference with the NSA’s possession of the data, Snowden said, is that government has the power to take away life or freedom.

At the NSA, he said, “there are people in the office who joke about, ‘We put warheads on foreheads.’ Twitter doesn’t put warheads on foreheads.”

Privacy, as Snowden sees it, is a universal right, applicable to American and foreign surveillance alike.

“I don’t care whether you’re the pope or Osama bin Laden,” he said. “As long as there’s an individualized, articulable, probable cause for targeting these people as legitimate foreign intelligence, that’s fine. I don’t think it’s imposing a ridiculous burden by asking for probable cause. Because, you have to understand, when you have access to the tools the NSA does, probable cause falls out of trees.”

In the first in-person interview Edward Snowden has conducted since his arrival in Moscow in June, Barton Gellman reports:

It is commonly said of Snowden that he broke an oath of secrecy, a turn of phrase that captures a sense of betrayal. NSA Director Keith B. Alexander and Director of National Intelligence James R. Clapper Jr., among many others, have used that formula.

In his interview with The Post, Snowden noted matter-of-factly that Standard Form 312, the ­classified-information nondisclosure agreement, is a civil contract. He signed it, but he pledged his fealty elsewhere.

“The oath of allegiance is not an oath of secrecy,” he said. “That is an oath to the Constitution. That is the oath that I kept that Keith Alexander and James Clapper did not.”

People who accuse him of disloyalty, he said, mistake his purpose.

“I am not trying to bring down the NSA, I am working to improve the NSA,” he said. “I am still working for the NSA right now. They are the only ones who don’t realize it.”

What entitled Snowden, now 30, to take on that responsibility?

“That whole question — who elected you? — inverts the model,” he said. “They elected me. The overseers.”

He named the chairmen of the Senate and House intelligence committees.

“Dianne Feinstein elected me when she asked softball questions” in committee hearings, he said. “Mike Rogers elected me when he kept these programs hidden. . . . The FISA court elected me when they decided to legislate from the bench on things that were far beyond the mandate of what that court was ever intended to do. The system failed comprehensively, and each level of oversight, each level of responsibility that should have addressed this, abdicated their responsibility.”

“It wasn’t that they put it on me as an individual — that I’m uniquely qualified, an angel descending from the heavens — as that they put it on someone, somewhere,” he said. “You have the capability, and you realize every other [person] sitting around the table has the same capability but they don’t do it. So somebody has to be the first.”