“I’d bet they’re asleep in New York. I’d bet they’re asleep all over America,” bemoans Rick the saloonkeeper in the classic 1942 film “Casablanca.”

As Humphrey Bogart mumbled those words on a Hollywood backlot, the world could not have been in worse shape. The swastika waved over Rick’s beloved Paris. Nazis boots were on the march everywhere. Nevertheless, “Casablanca” did a huge box office.

The story of Rick’s transformation from pacifist to patriot mirrored the shift in the national mood. In 1942, after Pearl Harbor, Americans were ready for a fight.

And fight they did. Monday, August 25 marks the 70th Anniversary of the liberation of Paris, one of the greatest symbols of the world winning back its freedom from Nazi domination.

Today, as on every occasion associated with the war, we pause to marvel at the accomplishments of the “Greatest Generation.” They are silver-haired and stoop shouldered, now. It is hard to imagine that passengers unloading from an Honor Flight (a tribute that flies veterans to Washington, D.C., to visit the national World War II memorial), were once leaping into the early morning darkness that shrouded Normandy.

Freedom’s future was won by youth. In the U.S., those between 18 and 41 were considered eligible for military service, but the average age of a combat soldier was around 26.

And it wasn’t just American youth that went to war. The first troops into Paris were units of the Free French. Their way was paved by the French Resistance, whose ranks were also filled with young men and women who fought to take freedom back.

At the time they had no idea that their generation was great or even good. Before WW II, many wondered if Americans still had the right stuff—if a GI could ever match-up to a doughboy.

The novelist James Michener, who served in the Pacific during World War II recalled, “Many observers considered us a lost generation and feared we might collapse if summed to some crucial battlefield.”

And there was measure of guilt that Americans had done too little to match the fascist menace from Germany and Japan. Army chaplain Russell Cartwright Stroup, another veteran of the Pacific war, wrote that he chose overseas service because he felt that, “as part of a generation that failed to prevent this war, I should suffer with those who are victims of our failure.”

But measure up they did. Sixteen million Americans put on a uniform. They fought on every continent except Antarctica. Almost half the U.S. economy was diverted to the war effort.

Many might say never again. By some estimates, about 75 percent of American youth are not even qualified for military service.

They also say Americans are sick of war. That America has no stomach for boots on the ground. They say America can’t afford to defend itself.

Hopefully, America’s youth will never have to liberate Paris again. But, it would be unwise to assume that this generation could not.

America has never been the same country. It has been weak and agrarian. It has been powerful and industrialized. The only common characteristic is that—whatever the era—they were all Americans. And, yet, every generation of Americans has proved to be the greatest generation. Every generation has answered the call to arms when it came.

Americans can and should always debate what are the best steps to take to keep Americans free, safe and prosperous. Nor should we ever take lightly the decision to answer the call of the trumpets.

From Continental Army soldiers enduring the privations of Valley Forge to GIs marching down the Champs Elysees, Americans have evidenced an enduring commitment to fight for freedom.

There is no reason to sell this generation of America’s youth short. That is not just a hope. It’s a fact. After over a decade of war, the fact that our armed forces continue to recruit and retain a high quality all-volunteer forces speaks volumes.

As we remember Paris, it is not just an opportunity to praise the past. It is a time to remember we should never sell our nation—especially our young people—short.