It seemed so still and bucolic at the military academies and war colleges of the country two weeks ago, the 202nd anniversary of the founding of our armed forces. Had Vietnam finally been fogotten?

In commencement speeches, it seldom came up. In conversations, even less. Yet it was there.

The most unnoted, unsung story of the U.S. military today is the fact that the Vietnam experience has gone underground and under skin, if you will, to the soul. It is now the subject of a deep and systematic search on the part of the intellectual military, who are determined their honor must never be so besmirched again.

Here at the lovely, pastoral Army War College, you find the center of the inquiry in the person of the commandant, Gen. DeWitt C. Smith Jr., who began the courses and seminars on ethics during the three years he has been here.

"We are thinking of the ethical implications of institutional practices," he told me thoughtfully. "The concept of 'zero defects' - can it lead people to cut corners and fudge? 'Can do' - does it lead people to do things without thinking? The code word 'bottom line' - is it totally stripped of ethical implications?

"We study My Lai and the body count as a measure of 'success.'" He paused and shook his head. "How did we ever come to use such an odious phrase? How did it come to be that some people allegedly changed statistics so thay looked advantageous?

"What . . . are the ethical implications of sending young men and women to fight with less than optimal national support and putting them in a climate where, while dying horrible deaths, we have a giant PX importing French perfume and nylons right behind them?

"Isn't there something ethically wrong in creating a kind of latter-day Roman Empire behind the lines at the same time young men are dying in the jungle? And what are the practical possiblities for doing it over again?"

If these are the questions, Col. William Rawlinson, who teaches the ethics courses, after months of study has come up with some answers.

They have pinpointed the MacNamarian style of Army "utilitarianism": In effect, the only things that count are the future consequences. Yet, duty and loyalty, the very soul of any military, respond to the present and the past.

While studying My Lai, they consider why the commanding general did not report the atrocity to higher authorities. Was he more selfishly concerned with himself and his advancement than with this duty?

Col. Rawlinson, sitting in his office here, which is filled with ethics books from Plato on down, said, "The crux of ethics in the military is this: First thing is to ask yourself who your client is. You say, "The client of the military is the people.' That's not good enough.

"Then you say, 'really, the client is the Constitution of the United States'. That's not good enough." He paused then said with emphasis, "The client of the military is the moral aspects of the Constitution of the United States."

What is fascinating is that this inner struggle, this moral search, is going on in different ways in every military institution. When I was at the Naval War College at Newport, R.I., recently, I found it taking the form of more of a careerist turn - how to live in the political bureaucracy (which, of course, is what sent them to Vietnam) and still remain an honorable officer.

Everywhere they concern themselves with the relevant but excruciatingly difficult question of when to stay within the system and keep quiet and when to resign. Everywhere, too, they are analyzing not only the "just war" theory (Col. Rawlinson has a cogent 10 points that are necessary for a just war) but even the "selective war" theories.

But - is there perhaps something intrinsic in the military profession, with its views of obedience, that makes honor, finally, a contradiction in terms?

Col. Malham Wakin, an outstanding philosophy professor at the Air Force Academy, posits the personal and ideological conflict: "What are those values you would give your life for? Precisely those liberal values of freedom, dignity, the right to choice and freedom of speech. Yet the first thing that happens to you is you discover that the foremost in military lifestyle is subordination to the will of the group - and thus conservavtive values."

Col. Wakin concludes that "the military mind, the military lifestyle, is one in which the realm of competence and the realm of morality are closer than in any."

Three years ago, after I had been in Vietnam myself and was disturbed by everybody's role in the war, I began looking for some ehical questioning here. There wasn't any. inside the military, the mood then was one of rage and betrayal. Outside, the predictions were of a military rebellion or a "stab-in-the back" reaction.

Today, instead, as Gen. Smith says, "There is no secret French organization in our military, no turning inward, no blame. It is a success story. As I look around, I see few countries less like Sparta."

He is certainly right - and so, perhaps, is Col. Wakin. It only seems paradoxical that the military is virtually the only institution deeply and philosophically studying our recent ethical quagmires of the soul. Yet it is precisely that military spirit and discipline that morally forces it to do so.