We never loved the bomb, but we did at least learn to stop worrying about it. According to new documentary Countdown to Zero, though, we shouldn't have. As Lucy Walker's film details, there's even more to worry about today: terrorists seeking to acquire nuclear materials, former Soviet countries trying to sell them, nuclear stockpiles, the club of nuclear-capable countries expanding to include states such as North Korea, Iran and Pakistan. Countdown to Zero has been described as the Inconvenient Truth of nukes, though judging by its terrifying revelations, our species is destined to destroy itself by nuclear means long before climate change gets a chance."
Unfortunately, there's nothing I learned making this film that made me less worried," says Walker. Like most British children of the 1980s, she remembers what it was like to live in the shadow of nuclear annihilation. It was an age of paranoia, nightmares and mutually assured destruction, absorbed through pop songs like Two Tribes, 99 Red Balloons, even Sting's Russians, or terrifying movies such as The War Game, Threads and The Day After. And let's not forget Raymond Briggs's cheerily apocalyptic graphic novel When the Wind Blows.
"I remember my dad saying you'd need to build a shelter, and you'd need a gun to keep the neighbors out," says Walker, "and my mother saying she'd take a suicide pill anyway. To hear these ideas coming out of the mouths of your otherwise sensible parents, it didn't compute. It was so shocking and outrageous."
Some of Countdown to Zero's horrifying near-misses wouldn't look out of place in Kubrick's Dr Strangelove. There are stories of nuclear bombs accidentally falling off planes and nearly vaporizing North Carolina, and "top secret" launch codes that everyone knew, and could have used any time they felt like it.
Another time, in what sounds like a real-life version of 99 Red Balloons, a weather satellite launch in Norway triggered a Russian alert so serious Boris Yeltsin was asked to press the button. He refused to believe it was a real attack, fortunately.
Even without the prospect of actual nuclear aggression, the film argues, nuclear weaponry is a disaster waiting to happen, as a result of the complex "fail-safe" systems the technology requires. The point has recently been demonstrated in Japan, with the meltdown of reactors at the Fukushima nuclear plant.
"Knowing what I know now, I wasn't surprised at all," says Walker. Her film deals solely with the military side of nuclear technology, but they're two sides of the same coin, she says. "If you watch Countdown to Zero, I don't think you're surprised that freakish events giving rise to accidents are not preventable, and should therefore be expected. These low-probability incidents aren't somehow made impossible by the fact that their consequences are so grave."
The gravity of the situation is hammered home by formidable experts and former heads of state, including Mikhail Gorbachev, Pervez Musharraf, Valerie Plame, Jimmy Carter and Tony Blair. Yes, Tony Blair, who told us we were 45 minutes away from an Iraqi WMD attack, weighing in on Iran's nuclear programme.
The irony is not lost on Walker. "Nuclear weapons were not his proudest moment," she says. "I was impressed he agreed to speak at all, and to answer questions about Iran and Iraq." Unlike others, Blair didn't impose conditions on her interview, she says. Musharraf, for example, would not discuss AQ Kahn, the scientist accused of passing on nuclear technology to North Korea, Iran and Libya. Unsurprisingly, North Korea and Iran refused requests outright, but the US defense department in effect denied Walker access by dragging out its approvals process. "They're still considering our request, two years later."
Dealing with world leaders is something of a departure for Walker. Her previous three films focused on intriguingly obscure communities: Amish teenagers exploring the outside world in Devil's Playground; blind Tibetan mountaineers in 2006's Blindsight; and workers at the world's largest landfill site, outside Sao Paolo, in last year's Oscar-nominated Waste Land. The latter is the type of reputation-making hit most documentary-makers dream of, an inspirational chronicle of Brazilian artist Vik Muniz's alchemical project to turn trash into art, and dignify some of the world's lowliest people. The complete opposite, in other words, of Countdown to Zero. They could have been made by two different people.
"I describe Waste Land as the antidote to this," she says. Countdown to Zero was made in between shooting and editing Waste Land, she says. "But they're similar in that I approached each of them with an open mind, and dived into a big subject I knew little about." Walker was "recruited" by Jeff Skoll, the billionaire philanthropist behind socially oriented film company Participant Media, and Lawrence Bender, producer of An Inconvenient Truth (and all of Quentin Tarantino's films). They were working with a non-profit thinktank called the World Security Institute, which has been campaigning against nuclear proliferation since the 1970s.
There was a lot to catch up on since the days of When the Wind Blows, says Walker. "Initially it was like they just threw me the car keys and I said, 'Wait a second, I don't know anything about nuclear weapons. Come back!' But I embarked on a ruthlessly thorough campaign to get the experts' experts and all their points."
You could accuse Walker's film of succeeding too well, and bringing 1980s nuclear paranoia to a whole new generation. Experts detail the horrific effects of a nuclear detonation over crowds of revellers in Times Square, five-mile radiuses are superimposed over shots of world cities – the area within which everyone would be instantly killed by a nuclear blast. There are predictions of mass panic, inadequate facilities, the breakdown of society. You can't help feeling a little powerless and vulnerable.
There is a suggestion of a happy ending, though. In 2008, the World Security Institute launched an initiative called Global Zero, backed by scores of political, religious and military heavyweights, which set out a political and scientific plan for total nuclear disarmament – the "countdown to zero" of the title. Civilian activists are encouraged to sign up and build Global Zero into an international movement.
They'll have their work cut out, though. In the film, Mahmoud Ahmadinejad defends Iran's adoption of nuclear technology with unassailable logic: "If it's a good thing, then we should have it, too. Why should only you have it? If it's bad, why do you have it?"
What good can a western anti-nuclear movement do? "Our best bet is nuclear weapon states exercising more leadership in reducing their arsenals," says Walker. "I think that's the only leverage we have. I would love the UK to show some leadership on this. It's not just down to the US and Russia; we have a lot of authority."
Can public opinion and documentaries really make a difference? Walker strongly believes so. "Talking to Gorbachev, and reading transcripts of the Reykjavik summit [between Reagan and Gorbachev, in 1986], I feel that all those CND protests and pop songs in the 80s actually did turn things around," she says. "They did cause Reagan and Gorbachev to change their minds – without question. Supposedly, Reagan was freaked out after watching The Day After on TV; Gorbachev changed his mind after Chernobyl." The all-out disarmament proposed at Reykjavik never happened – the US's Star Wars initiative was the stumbling block. "But I hope the people who really put their energy into protesting in the 80s can take some pride and satisfaction in what they achieved."
Apparently, Walker's film has already had a similar effect. Since Countdown to Zero was completed, a new strategic arms reduction treaty between Russia and the US (which own 96% of the world's nuclear arsenals) has been signed and ratified. Washington insiders have told Walker her film was an influence. The countdown has begun, then, but will it ever get to zero? "You can't just wave a magic wand," Walker says. "It's a considerable international diplomatic and scientific process, but I don't think it's naive to talk about it. I think it's naive to assume that disarming is more difficult than where we're headed if we don't. It's tough to get rid of nuclear weapons, but it's tougher to have them."
Countdown to Zero will be screened nationwide on 21 June as part of Demand Zero Day.