oliver stone
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Oliver Stone says that I will screw him over. He says it quite pleasantly, in that deep patrician voice of his, smiling at me over the coffee and muffins on our little table in a sleek wine bar in lower Manhattan.

His suspicion stems, I think, from something I say not long after we sit down. We're talking about America's National Security Agency and its efforts to harvest the world's data, as unveiled by the former NSA contractor Edward Snowden in documents he gave to journalists โ€” and retold, with a few embellishments, in Stone's film, Snowden, which stars Joseph Gordon-Levitt in the title role.

I mention chatting with a colleague, whose take on the whole Snowden affair was: "That is what spy agencies do, isn't it? They spy. What a surprise."

"That's the argument," says Stone, frowning. "What else did he say?"

Well, he mentioned the moment near the end of Laura Poitras's Oscar-winning documentary Citizenfour, when Snowden is about to leave the hotel room in Hong Kong where he has been holed up for days with three journalists: Poitras, Glenn Greenwald and Ewen MacAskill, and the rest of the world's media is buzzing about outside. Snowden is doing his hair in the mirror: he is trying to disguise himself. But I think my colleague saw it as a sign of something else: that Snowden had a self-aggrandising streak, a hero complex, and he was putting lives in danger by releasing all these documents.

My colleague works for a different section of the paper and has nothing to do with this interview. But Stone keeps returning to him, until it feels as if his spectre is looming over the untouched muffins. "I don't agree at all," Stone says. He met Snowden nine times in Moscow, while researching his biopic. "He is a very modest man and very shy."

Stone is dressed in a tweed jacket and a black poloneck. He has laid his hat and his thick-framed glasses on the table and draped his giant black coat over his chair. In his twenties he looked like a matinee idol: there's a picture of him in 1968 as a young infantryman, sitting in the doorway of a wooden hut in northern Vietnam, smouldering away. He was a child of privilege, a stockbroker's son who grew up in Manhattan and Connecticut, dropped out of Yale and joined up and requested combat service. He won the Purple Heart and the Bronze Star.

After film school on the GI bill, he made his way steadily into Hollywood and directed a streak of Oscar-winning movies: Platoon in 1986, Wall Street the following year and Born on the Fourth of July in 1989. He has continued at the same frenetic pace ever since: turning out hard-hitting political features, conspiracy films, biopics of Nixon, George W Bush and Alexander the Great and long, freewheeling documentaries about Fidel Castro, Hugo Chรกvez and the "untold" history of the United States.

"I've been criticised from the beginning for everything, with the exception of probably Platoon," he says. "Now, I hear a lot, 'He made his best films when he was young'. I'm working just as hard as I've ever worked and I'm doing the same kind of thing."

He has turned 70. His face is craggy, his eyebrows are bushy and his hair is the same jet black, flopping lankly over his head. He says that he will talk only for half an hour but it ends up being an hour. A short chat with Stone would be like a novella by Tolkien: impossible. For Stone, Mordor is America, which has been held responsible, by the end of our conversation, for nearly every bloody conflagration since the Second World War.

Stone compares Snowden to a refugee from the Nazis. "He's in Russia. In the 1940s he'd be here."

Snowden has been charged under America's Espionage Act, which makes no distinction between a whistleblower giving files to a journalist and a spy sending them to a foreign government. "He'd go to jail and be muzzled for ever," says Stone. "This is what your [colleague] should be asking. The only place in the world that can resist American rule now is Russia, or China maybe. Even China didn't want to give [asylum] to him because they're scared. What country in the world would give him asylum?"

In 2013, when Snowden was on the run, "Venezuela offered, as did Ecuador and Bolivia, but they're not strong enough to resist. The US sends commandos into every country in the world," Stone says. "We're living in a world that is basically uni-polar, which is the United States dominates and controls everything. I asked Putin, and he said, 'Look, I don't particularly admire what [Snowden] did,' because he'd been a KGB agent at one point in his life, but he said he admired his courage. He said the NSA had gone too far, a lot further than the Russians did because they had bigger money and more technology at that time."

Wait a minute. You asked Vladimir Putin? Stone nods.

"When I was doing the movie," he says. "I would just call him. I knew him because I met him, he got involved with us." Stone ended up making a documentary about Putin, as you do. They did a series of interviews together. It's out next year. "I'm sure I'll be eaten alive by the usual people," says Stone, glancing around as if looking for my colleague.

Stone says Putin might actually have sent Snowden home to the United States. "He said: 'We were negotiating with the United States an extradition treaty . . . The United States didn't want to sign because they have so many Russian criminals that stole money from the Russian state in the West, and they didn't want to return them.'"

Then Snowden shows up in the transit zone of Moscow airport. "[Putin] said: 'We don't have any treaty with you. We didn't make one. You didn't want one. Therefore, under Russian law, we will give him asylum.' "

Then Stone launches into a lecture about treaties America has broken: the anti-ballistic missile treaty, the eastward expansion of Nato. "Why should Russia co-operate with us? There is no answer except to say: 'You're the bad guy and we have the right to do anything we want'. Don't they realise that Russia has been invaded twice, lost 40 million people in two wars and are f***ing paranoid about it?"

Snowden, in his Moscow fastness, has actually criticised the Russian state's surveillance laws. Does he feel conflicted about living there?

"What choice [does he have]? He's a guest. As a guest, he's been critical. You also have a picture of Russia as some sort of Stalinist prison, which it is not."

No I don't, I splutter, but Stone forges on.

"First of all, they're not communists. That's the first thing the f***ing British don't understand." He launches into a lecture about Ukraine, Crimea and Latvia. But let's get back to Snowden, I say. How is he doing?

"I think he's settled and at peace with himself," says Stone. "He'd prefer to be in his own home country which he knows better. He likes fast food and all those American things, sure. I think he knows the price he paid, and he paid it willingly."

Stone had not intended to make a biopic about Snowden, even though it would fit neatly into his milieu. "I didn't think it would make a movie because it was too controversial," he says โ€” which I find surprising, coming from the man who made JFK, which contends that Kennedy's murder was part of a plot to preserve the interests of the military industrial complex.

Then Stone got a call from Snowden's Russian lawyer, Anatoly Kucherena, who had written a novel about an NSA leaker stranded in a Moscow airport. He hoped it could become a film. "He called and said, 'Can you come to Moscow? I'd like you to meet Mr Snowden', without Snowden knowing much about it."

Snowden was apparently concerned that it would seem as if he had sold the rights to his story, which he had not. Stone was sceptical too. And everyone was worried that they were being tailed or bugged. Stone only committed after their third meeting. He thinks Snowden co-operated "because he knew that he would get the right story out, because there were so many false stories going around".

The film makes plain all kinds of details we may have missed or forgotten. That Snowden joined an elite branch of the US military, but was forced to drop out because of his frail legs. That he sought another way to serve his country. That he was, essentially, a self-taught computer prodigy, who showed up at the CIA without a college degree and aced the entrance exams.

"He was a patriot," says Stone. He compares Snowden to Ron Kovic in Born on the Fourth of July, who fights in the Vietnam War "and then becomes a fierce fighter against it". The new film suggests that Snowden's girlfriend, Lindsay Mills, was central to his transformation. "They said she was a pole dancer and dismissed her widely," Stone says. "She was with him for those nine years we cover in the film."

It's strange to hear Stone โ€” whom I'd read about as a great, untamed womaniser (he has been married three times, the second marriage producing two sons, but has been with his third wife, Sun-jung Jung, for 21 years; they have a grown-up daughter) โ€” talking earnestly about this shy young man's love life. Snowden realised "he couldn't live without her," Stone says. "I think that from being a loner, he changed, and I don't think he ever had another girlfriend, as far as I know."

The film presents Snowden as an American hero who must forsake his love, and finds that she comes back to him, even in exile. At the climax, the man himself makes a cameo. "I think the greatest freedom that I've gained is that I no longer have to worry about what happens tomorrow, because I'm happy with what I've done today," he says.

Did Stone script this? "That was his. We obviously worked at it over a period of time, to get the right expression, because he didn't want to seem didactic. I wanted him to sound really emotional, and that's hard for him because he's a rationalist."

Snowden's lawyers clearly hoped the film might help to change public perceptions and perhaps even push President Obama to grant a pardon but Obama has said he can't pardon Snowden as he has not yet been convicted. "Which is nonsense," says Stone. "Gerald Ford gave a pardon to Richard Nixon before Nixon was even tried. Carter pardoned all the Vietnam draft resisters . . . Typical Obama, to skirt the issue, because he's a weak man and he won't come to grips with the good that Snowden did our society by alerting us to the fact that we have a far more comprehensive global surveillance system in operation than we ever believed."

Stone says he wanted to tell a gripping story, while also ensuring that he did "not to make up stuff". Some reviewers think it remarkably restrained, by his standards, though there are a few inaccuracies and Stone-ish flourishes. He links a program Snowden built in Japan with the America's drone programme, and it seems unlikely that Snowden went fowl hunting, regularly, with the deputy head of the CIA.

Possibly the most shocking allegation in the film, that the NSA slipped malware into the infrastructure networks of Japan and other friendly nations, which could be used wipe out power grids, dams and hospitals, may not be not far off the mark. Gordon-Levitt, as Snowden, says that "if the day came when Japan was no longer an ally it'd be lights out".

James Bamford, an investigative reporter and perhaps the most prominent historian of the NSA, shows me a slide Snowden smuggled out: a map of the world with yellow dots marking where the NSA had planted malware. I can't see any in Japan, but there are plenty in Brazil and Mexico, and a few in Europe. "The idea here is if someone takes over [in these countries] who is unfriendly, we already have our malware in there," says Bamford. "For intelligence, and we can use it as a weapon."

Stone says: "I'd love to know if we're doing it to France or Italy. I don't think [we are doing it] to Britain. [But] basically if you're not our ally, you're our hostage. We're bullies, and you are hostages. I hate to tell you that's the real fact. Your colleague is full of shit. He sees it as this beneficial American system. I don't agree."

He eyes me grimly across the table. It's hard for people to really realise what's going on," he says. "If the United States were to come out the bad end of this tube, which is quite possible, it would be nice to see all these people in a court of justice. [George W] Bush would be first one in, or Cheney. I think Obama goes, and they all go because they are doing these things."

Now Stone has to go to meet some people about a script. "You seem like an honest young man, but please don't let things get distorted," he says. "I've told you things that I feel. Please be careful." A little later I run into him in the gents. We make awkward small talk about the weather, as Stone stands at the urinal. I open the door to leave but hesitate because he is still talking. "I'll see you again," I say, and he nods.

"After you've screwed me over."