"Countdown to Zero," directed by Lucy Walker, is a stunning documentary about the escalating global nuclear arms crisis. The film explores the dangers of nuclear weapons, exposes a variety of present-day threats, and features insights from a host of international leaders and thinkers.

Among the voices are Jimmy Carter, Mikhail Gorbachev, Tony Blair, Pervez Musharraf, former CIA Operations Officer Valerie Plame Wilson, Ploughshares Fund President Joe Cirincione, and Stanford political scientist Scott Sagan.

They all say basically the same thing: our only option is to create a world without nuclear weapons. Luckily, it's possible to achieve that step by step.