How does one breathe new life into an issue that is sixty-five years old? How does one awaken the public to hear a warning that, like a car alarm that went off outside one’s window decades ago and never stopped screeching, is still disturbing the peace yet remains unheard? I am speaking, of course, of the nuclear peril, born in 1945, and still going strong. The comparatively new organization Global Zero, which was founded in 2007 and calls for the abolition of nuclear weapons by 2030, has been making the effort. In its attempt, it joins older organizations such as Peace Action, the Physicians for Social Responsibility and the Nuclear Age Peace Foundation, to name just a few. The group’s co-directors are Bruce Blair, a former missile control officer who became a world expert on nuclear command and control, and Matt Brown, formerly secretary of state for Rhode Island. They have won the support of a great number of the remarkable array of retired officials, including many of the two-thirds of former secretaries of state, former secretaries of defense and former national security advisers who have come out for nuclear abolition. Half a million people have signed the group’s statement calling for a nuclear-weapons-free world. (I am a signer.) Now Global Zero seeks to win wider public support. To this end, it has joined forces with Lawrence Bender, who produced the unexpectedly blockbusting movie An Inconvenient Truth, the film version of Al Gore’s famous slideshow about global warming, to make a film, Countdown to Zero, about the state of things nuclear today. The director is Lucy Walker, best known for her documentary Blindsight. The film opened on Friday in New York and Washington and will open in twenty more cities on July 30.

Global warming and nuclear danger of course have a great deal in common. In both, the biosphere is at stake. In the face of both, the public has shown a marked tendency to tune out. But other things are different. Worry about global warming is relatively new. By contrast, waves of concern about nuclear danger have come in and gone out many times—in the late 1940s, in the mid-’50s, in the early ’80s. The key facts have almost all been taught and retaught. And again and again they have been forgotten and re-forgotten. Those who teach the subject, as I do, find that the generation now coming of age, through no fault whatsoever of its own, has less fundamental knowledge about nuclear matters than any before it. In this field, it sometimes seems, the more that we learn, the less we know.

And yet the job of public education cannot be merely to re-stuff old minds with material that fell out of them since the end of the cold war. Venerable as nuclear danger is, it has changed shape, and some aspects are new. Proliferation has proceeded apace, and now there are nine nuclear powers and any number of others in the wings (especially in the Middle East). The fear that a terrorist group might steal or build and use a nuclear bomb in one of the world cities has rightly gripped the public imagination.

The job, therefore, of making a film that is neither just a howl of alarm (justified as that would be), nor just a classroom primer (indispensable as that would be), nor just a historical account (fascinating and revelatory as that would be in a time when historical findings have been especially interesting) is daunting indeed. In the face of these contradictory challenges, Countdown to Zero succeeds powerfully. It is an absorbing, deeply informative, often shocking yet completely reliable presentation of the fundamental architecture of the issue as it exists today. One important decision by the filmmakers was to proceed backwards through time. In a gesture that is more than a gimmick aimed at bringing novelty to over-familiar images, the film begins by showing in reverse motion the consequences of nuclear test explosions on sacrificial structures. A boiling cloud of smoke assembles a house. A sheet of fire creates a radio tower. Using dismaying interviews with captured smugglers of highly enriched uranium as well as scientists, the film marches through a sort of catechism on the availability of nuclear weapons. Can freelance scientists make nuclear weapons? Yes, if they can get nuclear weapon materials—highly enriched uranium or plutonium. (Scientists who appeared before a classified session in the Senate alleged that they could make the uranium variety of such a bomb, though sans the uranium—and, challenged by senators, did so, actually bringing the object to a later Senate session.) Can criminals obtain highly enriched uranium? Yes, and they have done it, by stealing it in Russia. (One thief explains that he wanted a refrigerator and a "gas stove." Another aimed higher: "I like Lamborghini, and Jaguar.") Can they smuggle it out of Russia? Yes. Can they smuggle it into the United States undetected? Certainly.

The focus shifts to accidental nuclear war, including the fearsome incident in 1995 when the Russian military mistook a Norwegian weather rocket for an American nuclear attack, and the infamous "briefcase" containing the codes for a nuclear retaliatory attack was opened for a decision by President Boris Yeltsin, who had the good sense to ignore the report. A presentation of proliferation ensues, including the story of the father of the Pakistani bomb, A.Q. Khan, who went on to peddle his wares to Iran, Iraq, Libya and North Korea, among other places.

At this point, the knowledgeable viewer may start to worry that the film regards nuclear weapons solely as something whose use threatens the United States but not something with which the United States (inventor and sole user of the bomb) has long threatened others. But the worry is quickly dispelled. In a particularly powerful and perhaps newsworthy episode, Blair reveals that when he was a missile control officer in the 1970s it was technically within his power to precipitate the launching of not only the fifty missiles in his squadron but the entire US missile force. Secretary of Defense Robert McNamara had tried to rule out just such an unauthorized launch by requiring the prior receipt of a twelve-digit launch code from headquarters, but the Strategic Air Command had neutralized the requirement by setting the code at 000 000 000 000, as the control officers well knew. In an interview, Blair explained that once that code was known a launch order could be formatted, and this, when conveyed by ultra high-frequency radio—or any other medium—would enable other crews to launch without further authorization of higher command. "They could take the code off the lid of a TV dinner, and as long it was correct it, would be carried out," he commented.

The film ends with interviews with ordinary people as well as distinguished persons (former Secretary of State James Baker, Mikhail Gorbachev, Jimmy Carter, Tony Blair) calling for a world free of nuclear weapons.

As it happens, two other excellent films on nuclear danger are newly available, though not in theaters. The first is The Nuclear Tipping Point, featuring interviews with former Secretary of State George Shultz, former Secretary of State Henry Kissinger, former Senator Sam Nunn and former Secretary of Defense William Perry. The four published a famous article in the Wall Street Journal in 2008 calling for a nuclear-weapons-free-world. It paved the way for the wave of support for nuclear abolition by retired officialdom that now joined Global Zero, but the four did not appear in Countdown to Zero, apparently reserving themselves for their own movie. Antinuclear veterans will be pleased to hear Shultz, the guiding spirit of this group, speak of the "horror" and "inhumanity" of the weapons. Also notable is Nunn’s statement that the American and Russian persistence twenty years after the end of the cold war in holding one another hostage to nuclear destruction on hair-trigger alert borders on "insanity."

Another new film, The Forgotten Bomb, directed and written by the independent film-maker Bud Ryan (it does have an interview with Shultz), uses riveting footage, some of which I have never seen before, to produce a subtle and fascinating portrait of the processes by which the United States has so frequently and so successfully purged its own consciousness of remembrance of its policies and deeds in the nuclear arena.

One question is how even a film as effective as these will be received in the present atmosphere, in which the nuclear issue is paradoxically both superannuated (shouldn’t we have got rid of these things at the end of the cold war—or a lot earlier?) and unknown, or perhaps one should say, de-known, since abundant information has been available for so long. (The difference between de-knowing and forgetting is that when you forget, something falls out of your mind; whereas when you de-know it, you expel it from your mind.) Global Zero has been organizing on campuses, among other places, and I asked Blair how things had been going. "The film has resonated in different ways," he said. "Older people are reminded that the danger is still there. Younger people are shocked to hear that it didn’t go away. Many college students had not been born when the Berlin Wall went down. They are blown away by the issue. They frankly didn’t know it ever existed, so for them it’s a revelation and discovery. Many consider the cold war to have been an insane period in their parents’ generation. The whole thing makes them pretty upset and even angry."

Upset? Angry? These are highly appropriate responses that have been conspicuous by their rarity in the nuclear arena in recent years. Their return offers hope of long-awaited change.