Currently available on DVD: "Countdown to Zero"

Illustrating the many ways nuclear weapons could kill you makes Countdown to Zero one of the most frightening documentaries you'll ever see, or endure.

Writer-director Lucy Walker doesn't uncover anything new, but building on interviews with experts and leaders including Jimmy Carter and Mikhail Gorbachev, she puts together an impressively urgent document. In one segment, we learn how poorly guarded nuclear material is in Russia, where a guy (who wanted money to buy a Jaguar) once nearly succeeded in smuggling out the heart of a bomb. Another recounts the follies of U.S. military planes that crashed while carrying nukes, another the Strangelovian moments in which the U.S. and Russia nearly stumbled into total war.

Then there are the really alarming scenes.

We learn from physicists that making highly enriched uranium is well within the capacity of many countries, and that with such material in hand, making a nuclear bomb is a cinch. Near the end comes a nauseating description of the cascade of woe that would result from a nuke being detonated in Times Square.

A fatuous happy ending calling for "diplomacy" and "treaties" suggests the future lies in a nuclear-free world. But how is determined discussion working out when it comes to the Iranian menace? The now-famous ex-CIA figure Valerie Plame Wilson (pictured above in a scene from the film) unambiguously says, "Without question, Iran is trying to get a nuclear bomb." Yet the movie simply hurries along -- without pausing to consider whether Iran might be stopped from crossing this deadly line.