I don't know whether President Obama's evocation of the Cold War in his State of the Union address on Tuesday night will have any effect on national morale, but I'm grateful to him for offering what, in that ghastly phrase, is a "teachable moment." It was only one searing episode in the long struggle against expansionist communism that Obama brought to mind: The surprise Soviet launch of the first Earth-orbiting satellite in 1957. The incident shocked the West, sparking the creation of the American space program and, as the president put it, unleashing "a wave of innovation that created new industries and millions of new jobs."

In retrospect, it's hardly surprising that the soft, degenerate West was able to outcreate, outlaunch, and outlast the brutal collectivist Soviet empire. Of course free people will be able to innovate better than automatons in a command-and-control economy. Innovation means trying new things, and that can only happen when people have the liberty to pursue their ideas.

At the time, though, American victory in the Cold War was not a foregone conclusion. We faced an implacable enemy. Only months before Sputnik rocketed into space, Premier Nikita Khruschev told the West that history was on the Soviets' side, and warned: "We will bury you!" Many in the West believed him.

This week, parents have been on the spot about the Sputnik episode, filling in for children what the president was talking about. After all, what's a satellite from the primitive days of black-and-white TV to them?

I don't think it's enough to say: "Well, kiddies, it was a time of American resolve." We need to go further. We need to explain to children just who we were up against at the time, a time of existential struggle against an evil ideology that, appallingly, still festers in corners of the world today.

It can be difficult to convey to children the enormity of Soviet communism but we have, at this very moment, an excellent tool for doing so.

Peter Weir's new film, "The Way Back," dramatizes the story of a multinational group of political prisoners who escaped from a Siberian gulag in the dead of winter, and walked 4,000 miles across Russia, across the Gobi Desert, and across the Himalayas into India.

The film is based on the true story of three Polish inmates. More importantly, it shows the truth of Soviet communism: How it destroyed lives and families, imprisoned and deceived and tortured and enslaved, and how it spread like a noxious disease across Europe and Asia. At one point in the film, the ragged band of escapees makes it to the Mongolian border only to see, terrifyingly, the hammer and sickle. "They're communist!" one of the prisoners gasps, and in that breath carries all the horror of their predicament.

That scene alone is worth showing to American schoolchildren who, even today, may hear from their teachers the disgraceful relativism that "real communism has never been tried."

Take your children to see this film. It's rated PG-13 but easily comprehensible (and not unduly shocking) for children as young as 10. It tells a story that they need to know. Let it inform their Sputnik moment.

Meghan Cox Gurdon's column appears on Sunday and Thursday. She can be contacted at mgurdon@washingtonexaminer.com.