Since the late 1960s, when Americans, in and out of uniform, began having second thoughts about their military history, the Air Force Academy has organized regular symposia on its major themes.

The most recent meeting, convened on the eve of the 75th anniversary of Kitty Hawk, almost inevitably commemorated the Wright brothers' pioneer flight. But the real theme was what air forces are good for and -- at least implicitly -- whether the past is a very helpful guide to the future.

Perhaps because it has such a relatively short history of its own, perhaps because its very origins testify to a particular conjunction of technology and politics, the Air Force takes history seriously. Military history is a staple in the academy curriculum. The service's official history program is among the best of its kind.

As even the dreaming Steve Canyon has been reminding us, the history of military aviation is only a little younger than aviation itself. Within 15 years of that memorable Dec. 17, 1903, Col. Blimp himself acknowledged that the flying machine was a useful addition to the military inventory.

Meanwhile, younger officers already anticipated an era when air power would accomplish what armies and navies hadn't or couldn't.

"The advent of air power, which can go straight to the vital centers and either neutralize or destroy them, has put a completely new complexion on the old system of making war," Billy Mitchell declared in 1930. "It is now realized that the hostile main army in the field is a false objective, and the real objectives are the vital centers."

This was the British and, with modifications, the German view a decade later. To the extent there was one, it was the American view, too. "America's air doctrine for years has been based solidly on the principle of long-range bombardment," Gen. H. H. Arnold confirmed in 1943. "Air forces are strictly offensive in character."

Bombers begat bombers -- the B17 in 1936, the B29 in 1944, the B36 and B47 in 1948, the B52 in 1952. Bombs begat The Bomb. In 1947 America's airmen flew the nest for organizational independence and what was believed to be the front line of military technology and strategic roles.

It turned out instead to be the world of Korea, Sputnik and its proliferating offspring, the Cuban missile crisis, "brushfire" warfare and Vietnam. By 1970, the B52, once conceived as the ultimate strategic bomber, was being used for close infantry support.

Without the ghosts, the meeting in Colorado Springs might have been an old-fashioned military reunion, or a nostalgic celebration of "those magnificent men in their flying machines." But there was no way around the ghosts. Since the entire history of aviation, let alone the Air Force, falls within the lifetime of surviving witnesses, some were even there to tell what it was like.

Historians recalled the legendary British general, anxious that newly acquired airplanes would scare the horses. They reconstructed the battles for autonomy won by European airmen after World War I, but by American airmen only another war later. They analyzed the long march to doctrinal and organizational maturity -- the sponsors' word -- since 1945. The word "missile" was heard only rarely in the proceedings.

The course of events, the historians suggested, had taken the Air Force onward but not necessarily upward. The generals concurred as they recalled the challenges of World War II and the Berlin airlift, but also the multiple frustrations of Vietnam.

It was a member of the Vietnam panel who tried hardest to produce evidence of success. Conversely, there was an elegiac note from the victors of World War II, including Gen. Curtis E. LeMay. Creator of the Strategic Air Command, which dominated the service for a generation after the war, LeMay was Air Force chief of staff from 1961 to 1965.

"Old men usually think the world is going to hell in a hand basket," LeMay observed. There was no question that he did, and that for him and others the wild blue yonder had turned inexplicably grey and cloudy.

A man whose active career spanned the adventuresome 1930s, the strategic bombing campaigns in Europe and the Pacific and the bomber-based deterrence of the 1950s, LeMay virtually personifies the history of the U.S. Air Force.

But he found it hard to put himself in historical perspective. "We all understand the importance of your career," one questioner asked from the floor, "but I wonder how much of it you think might be peculiar to the times, or what parts of it can't or shouldn't be repeated."

There was some self-conscious laughter and a bit of applause from the audience. The panel, and LeMay himself, only looked puzzled. He wasn't sure he understood the question, he said. But if he had to do it once more, he replied in effect, he guessed he wouldn't want to be caught unprepared again for World War II.

The answer was revealing and attractively honest.But it might not have been much help to cadets and officers who have to live with SALT, sea-based Tridents, ultra-sophisticated air defenses and the conceivable end of the land-based missile.

Today's Air Force has long since conceded that deterrence is too important to leave exclusively to generals in sky-blue uniforms. The cancellation of the B1 bomber is likely to have been the end of a chapter, if not an era, in Air Force history.

The new challenges of tactical air power, military transport, and so on, may be missions enough for the future. But this has hardly been the traditional Air Force view, or the traditional American reason for funding and maintaining an air force.

And so a conference commemorating Kitty Hawk ended with an authentic historical lesson. It was that history can be an inspiration for a service as sure as ever of its esprit, its organizational skill and its technical brilliance.

But it can also be a burden for a service designed for one world, and scrambling to find its role in another and quite different one.