I KINDA STOPPED WORRYING about nuclear fallout sometime after WarGames. That's over 20 good years of resting easy! Alas, now I'm back to gnashing my teeth and nervously ducking under my desk anytime I hear a loud bang. Thanks, Countdown to Zero.

In 1961, John F. Kennedy said, "[We] live under a nuclear sword of Damocles, hanging by the slenderest of threads, capable of being cut at any moment by accident, or miscalculation, or by madness." Documentarian Lucy Walker sets out to remind us how true JFK's statement still is, starting by interviewing a Russian who easily stole and attempted to sell a large amount of highly enriched uranium, the key ingredient in making a nuclear bomb. "Potatoes were better guarded," says one interviewee about Russian security measures taken to safeguard the radioactive ingredient. So if it isn't worrisome enough that terrorists could easily purchase and smuggle uranium, how about the fact that it has become downright simple to construct a crude nuclear bomb capable of blowing up any major city center? It's so easy, grad students do it for homework at MIT.

As far as "miscalculations" and "accidents," Countdown to Zero touches on the harrowing Cold War-era missile faceoff still going on between the US and Russia. Both countries are poised to destroy each other within 30 minutes, with two military lieutenants ready to turn their armament keys whenever their radar shows suspicious activity (like, say, a flock of geese). Countdown steers clear of scare tactics, instead relying on a steady stream of facts, illustrations, and excellent interviews with the likes of Mikhail Gorbachev, Valerie Plame Wilson, and Jimmy Carter. As nuclear disarmament becomes the cause du jour, Countdown to Zero provides fuel for the fire, rightful indignation, and, more than anything, a huge, glaring reminder that the possibility of nuclear annihilation is not an '80s retro throwback.