As they do every five or so years when the calendar turns to 6 June, presidents and prime ministers are descending on Normandy to commemorate the D-Day landings. They will intone about the price of freedom, draw parallels between today and yesterday, and somehow try to associate themselves with the heroes of Normandy. Of course, the more someone learns about D-Day, the clearer it becomes how unique that day and the men who lived it were.

Just consider Gen. Marshall’s orders to Gen. Eisenhower: “Cross the channel, enter the heartland of Germany and free the continent of Europe.” To secure that mammoth objective, Gen. Eisenhower hurled 160,000 men, 6,000-plus ships, 2,300 planes and 840 gliders across the English Channel. The U.S. element of the invasion force lost 2,500 dead in the first 24 hours—more than the United States has lost in Afghanistan in 13 years.

That’s how enormous and momentous and staggering in scope D-Day was—and remains 70 years later. Not surprisingly, it offers lessons for today.

First, deterring war is preferable to the alternatives: waging war or surrendering liberty. The past 2,000 years of history illustrate that peace through strength works. It’s far less costly in treasure and blood than scrambling to respond to aggression, rescue fallen continents or recover lost freedoms. For evidence, compare the costs of liberating Europe, North Africa and the Pacific Basin with the costs of deterring the Red Army.

Of course, if the sequestration guillotine falls with full force, much of America’s deterrent strength will be sacrificed. As Washington hacks away at the big stick, China’s military-related spending has grown 170 percent in the past decade, giving it the confidence and capability to challenge America’s once-unquestioned primacy in the Pacific; and Russia, in the midst of a 108-percent increase in military spending, is trying to reverse the once-settled outcomes of the Cold War.

Second, alliances are important. D-Day involved American, British, Canadian and French forces. On this foundation of alliances, the Atlantic Charter was written, Hitler and Tojo were defeated, the Berlin Airlift was launched and West Berlin saved, Germany and Japan were rehabilitated, NATO was built, and the Cold War was won. Today, as Moscow redraws Europe’s map, the NATO alliance is as important as ever. Indeed, there’s a reason Putin has dismembered Georgia and Ukraine with impunity while keeping his hands off the Baltics and Poland. That reason is NATO. However, if NATO’s members don’t start taking NATO’s all-for-one collective defense clause seriously—and soon—one wonders how long Putin will.

A third D-Day lesson comes courtesy of the man who commanded the invasion force. The night before the landings, Gen. Eisenhower scribbled a short note that spoke volumes about its author. “Our landings in the Cherbourg-Havre area have failed to gain a satisfactory foothold, and I have withdrawn the troops,” the general of generals wrote. “My decision to attack at this time and place was based upon the best information available. The troops, the air and the Navy did all that bravery and devotion to duty could do. If any blame or fault attaches to the attempt, it is mine alone.”

Ike’s words are a study in responsibility and leadership. As NPR’s Scott Simon observes, “It’s telling to see today where Eisenhower made changes in his note. He crossed out ‘This particular operation’ to write ‘My decision to attack,’ which is emphatic and personal. And he drew a long, strong line under ‘mine alone.’”

Gen. Eisenhower’s letter is a striking contrast from what passes for leadership, responsibility and courage nowadays: public servants hiding inside legal labyrinths to avoid responsibility; “courageous” whistleblowers fleeing to Russia rather than taking a stand in the open; billion-dollar bailouts and multi-million-dollar memoirs rather than consequences for bad corporate or public policy; policymakers blaming the other party or their predecessors for their own failures.

Fourth, some things are worth fighting for (or against). The hard truth is that we’re in the midst of a war. It may a different kind of war, but as in 1944, it’s a battle for our way of life, for freedom, for civilization itself. Too many of our countrymen fail to grasp this. Instead, they try to airbrush “war” out of our lexicon, even as Americans fight and die in battle; speak of “man-caused disasters” rather than terrorism; convince themselves that words—“the receding tide of war,” “leading from behind,” “red lines,” the “Pacific Pivot,” “bring back our girls”—are somehow equal to actions; talk of deploying troops to defend “our vital national interest” in the same breath as promising to begin withdrawing troops. It’s difficult to imagine FDR putting an expiration date on “our vital national interest” on, say, D-Day Plus 10—or perhaps a better parallel, Ike or JFK announcing plans to withdraw U.S. forces from West Berlin or South Korea.

Fifth, America remains indispensable. No country enfolds the full spectrum of power (economic, military, cultural) and embraces universally appealing attributes (political pluralism, rule of law, economic opportunity, cultural openness) like the United States. To be sure, some countries possess some of these attributes, but only the United States enfolds all of them. No matter what the declinists say, this confluence of strengths gives the United States an edge in the 21st century. No matter what the isolationists say, this confluence of strengths gives the United States a special responsibility to serve as civilization’s first responder and last line of defense. And no matter what those who yearn for a “post-American world” say, this confluence of strengths makes America indispensable and exceptional.

That leads to a sixth and final D-Day lesson. Americans have every reason to be patriotic and proud about yesterday—and optimistic about tomorrow. Sadly, the patriotic optimism so characteristic of the World War II Generation is something many of their children seem to scorn and many of their grandchildren and great-grandchildren simply don’t understand.

With their blood and sweat, the heroes of Omaha Beach and Utah Beach freed a continent. Most of us will never grasp what it cost to preserve our freedom, what they endured, what they saw, what they left on the battlefield, what they carried home. Of course, hundreds of thousands of them never made it home. But those who did would build “The American Century.” The least we can do in return is to revive the free-enterprise system they handed down to us, keep our word in international dealings and defend those who defend us.

If we do these things, the 21st century will be another American century. If we don’t, it will be shaped by someone else. For a preview of what that might look like, take a glance at what’s happening in Eastern Europe and the Western Pacific.

Alan W. Dowd is a senior fellow with the Sagamore Institute, where he heads the Center for America’s Purpose.

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