The late World War II combat veteran and memoirist E. B. Sledge enshrined his generation of fellow Marines as “The Old Breed” in his gripping account of the hellish battle of Okinawa. Now, most of those who fought in World War II are either dead or in their nineties.

Much has been written about the disappearance of these members of the Greatest Generation—there are now over 1,000 veterans passing away per day. Of the 16 million who at one time served in the American military during World War II, only about a half-million are still alive.

Military historians, of course, lament the loss of their first-hand recollections of battle. The collective memories of these veterans were never systematically recorded and catalogued. Yet even in haphazard fashion, their stories of dropping into Sainte-Mère-Église or surviving a sinking Liberty ship in the frigid North Atlantic have offered correctives about the war otherwise impossible to attain from the data of national archives.

More worrisome, however, is that the collective ethos of the World War II generation is fading. It may not have been fully absorbed by the Baby Boomer generation and has not been fully passed on to today’s young adults, the so-called Millennials. While U.S. soldiers proved heroic and lethal in Afghanistan and Iraq, their sacrifices were never commensurately appreciated by the larger culture.

The generation that came of age in the 1940s had survived the poverty of the Great Depression to win a global war that cost 60 million lives, while participating in the most profound economic and technological transformation in human history as a once rural America metamorphosed into a largely urban and suburban culture of vast wealth and leisure.

Their achievement from 1941 to 1945 remains unprecedented. The United States on the eve of World War II had an army smaller than Portugal’s. It finished the conflict with a global navy larger than all of the fleets of the world put together. By 1945, America had a GDP equal to those of Germany, Japan, the Soviet Union, and the British Empire combined. With a population 50 million people smaller than that of the USSR, the United States fielded a military of roughly the same size.

America almost uniquely fought at once in the Pacific, Asia, the Mediterranean, and Europe, on and beneath the seas, in the skies, and on land. On the eve of the war, America’s military and political leaders, still traumatized by the Great Depression, fought bitterly over modest military appropriations, unsure of whether the country could afford even a single additional aircraft carrier or another small squadron of B-17s. Yet four years later, civilians had built 120 carriers of various types and were producing a B-24 bomber at the rate of one an hour at the Willow Run factory in Michigan. Such vast changes are still difficult to appreciate.

Certainly, what was learned through poverty and mayhem by those Americans born in the 1920s became invaluable in the decades following the war. The World War II cohort was a can-do generation who believed that they did not need to be perfect to be good enough. The strategic and operational disasters of World War II—the calamitous daylight bombing campaign of Europe in 1942-43, the quagmire of the Heurtgen Forest, or being surprised at the Battle of Bulge—hardly demoralized these men and women.

Miscalculations and follies were not blame-gamed or endlessly litigated, but were instead seen as tragic setbacks on the otherwise inevitable trajectory to victory. When we review their postwar technological achievements—from the interstate highway system and California Water Project to the Apollo missions and the Lockheed SR-71 flights—it is difficult to detect comparable confidence and audacity in subsequent generations. To paraphrase Nietzsche, anything that did not kill those of the Old Breed generation made them stronger and more assured.

As an ignorant teenager, I once asked my father whether the war had been worth it. After all, I smugly pointed out, the “victory” had ensured the postwar empowerment and global ascendance of the Soviet Union. My father had been a combat veteran during the war, flying nearly 40 missions over Japan as the central fire control gunner in a B-29. He replied in an instant, “You win the battle in front of you and then just go on to the next.”

I wondered where his assurance came. Fourteen of 16 planes—each holding eleven crewmen—in his initial squadron of bombers were lost to enemy action or mechanical problems. The planes were gargantuan, problem-plagued, and still experimental—and some of them also simply vanished on the 3,000-mile nocturnal flight over the empty Pacific from Tinian to Tokyo and back.

As a college student, I once pressed him about my cousin and his closest male relative, Victor Hanson, a corporal of the Sixth Marine Division who was killed on the last day of the assault on Sugar Loaf Hill on Okinawa. Wasn’t the unimaginative Marine tactic of plowing straight ahead through entrenched and fortified Japanese positions insane? He answered dryly, “Maybe, maybe not. But the enemy was in the way, then Marines took them out, and they were no longer in the way.”

My father, William F. Hanson, died when I was 45 and I still recall his advice whenever I am at an impasse, personally or professionally. “Just barrel ahead onto the next mission.” Such a spirit, which defined his generation, is the antithesis of the therapeutic culture that is the legacy of my generation of Baby Boomers—and I believe it explains everything from the spectacular economic growth of the 1960s to the audacity of landing a man on the moon.

On rare occasions over the last thirty years, I’ve run into hard-left professors who had been combat pilots over Germany or fought the Germans in Italy. I never could quite muster the energy to oppose them; they seemed too earnest and too genuine in what I thought were their mistaken views. I mostly kept quiet, recalling Pericles’s controversial advice that a man’s combat service and sacrifice for his country should wash away his perceived blemishes. Perhaps it’s an amoral and illogical admonition, but it has nonetheless stayed with me throughout the years. It perhaps explains why I look at John F. Kennedy’s personal foibles in a different light from those similar excesses of Bill Clinton. A man, I tend to think, should be judged by his best moments rather than his worst ones.

Growing up with a father, uncles, and cousins who struggled to maintain our California farm during the Depression and then fought in an existential war was a constant immersion in their predominantly tragic view of life. Most were chain smokers, ate and drank too much, drove too fast, avoided doctors, and were often impulsive—as if in their fifties and sixties, they were still prepping for another amphibious assault or day-time run over the Third Reich. Though they viewed human nature with suspicion, they were nonetheless upbeat—their Homeric optimism empowered by an acceptance of a man’s limitations during his brief and often tragic life. Time was short; but heroism was eternal. “Of course you can” was their stock reply to any hint of uncertainty about a decision. The World War II generation had little patience with subtlety, or even the suggestion of indecision—how could it when such things would have gotten them killed at Monte Cassino or stalking a Japanese convoy under the Pacific in a submarine?

After the stubborn poverty and stasis of the Great Depression, the Old Breed saw the challenge of World War II as redemptive—a pragmatic extension of President Franklin Roosevelt news-conference confession that the “Old Dr. New Deal” had been supplanted by the new “Dr. Win-the-War” in restoring prosperity.

One lesson of the war on my father’s generation was that dramatic action was always preferable to incrementalism, even if that meant that the postwar “best and brightest” would sometimes plunge into unwise policies at home or misadventures abroad. Another lesson the World War II generation learned—a lesson now almost forgotten—was that perseverance and its twin courage were the most important of all collective virtues. What was worse than a bad war was losing it. And given their sometimes tragic view of human nature, the Old Breed believed that winning changed a lot of minds, as if the policy itself was not as important as the appreciation that it was working.

In reaction to the stubborn certainty of our fathers, we of the Baby Boomer generation prided ourselves on introspection, questioning authority, and nuance. We certainly saw doubt and uncertainty as virtues rather than vices—but not necessarily because we saw these traits as correctives to the excesses of the GIs. Rather, as one follows the trajectory of my generation, whose members are now in their sixties and seventies, it is difficult not to conclude that we were contemplative and critical mostly because we could be—our mindset being the product of a far safer, more prosperous, and leisured society that did not face the existential challenges of those who bequeathed such bounty to us. Had the veterans of Henry Kaiser’s shipyards been in charge of California’s high-speed rail project, they would have built on time and on budget, rather than endlessly litigating various issues as costs soared in pursuit of a mythical perfection.

The logical conclusion of our cohort’s emphasis on “finding oneself” and discovering an “inner self” is the now iconic ad of a young man in pajamas sipping hot chocolate while contemplating signing up for government health insurance. Such, it seems, is the arrested millennial mindset. The man-child ad is just 70 years removed from the eighteen-year-olds who fought and died on Guadalcanal and above Schweinfurt, but that disconnect now seems like an abyss over centuries. One cannot loiter one’s mornings away when there is a plane to fly or a tank to build. I am not sure that presidents Franklin Roosevelt, Harry Truman, and Dwight Eisenhower were always better men than were presidents Bill Clinton, Barack Obama, and Donald Trump, but they were certainly bigger in the challenges they faced and the spirit in which they met them.

This Thanksgiving, let us give a toast to the millions who are no longer with us and the thousands who will soon depart this earth. They gave us a world far better than they inherited.