THE MOST POWERFUL political idea of our time, surely, is the idea of World War II. For here we are, nearly 40 years later, and the World War II experience is still controlling American policy, still defining "national security" in a false and dangerious manner, raising brave banners and launching the wrong ships.

The junior officers from World War II, it has been said, run American politics and policy. They do still, inspired by their complicated memory of that great struggle.

The memory is moralistic: America restores right in the world, at great sacrifice. It is also cynical: The might of arms, of industrial mass, conquers all before it.And vigilant: America will not be tricked again; next time we will outtrick the enemy. And glorious: The finest hours of American memory are connected to wars and this was the finest war of all.

For a few brief years, after the disgrace in Indochina, when revisionist inquiries were exposing the crimes of the CIA and other action arms of the national-security state, it seemed that, perhaps, the World War II mindset was finally in eclipse. New premises for American world policy would surely emerge, now that the old premises were so tarnished with misspent blood and treasure.

Not to be.Probably not in our lifetime. As old warriors pass from the political scene, they are replaced by new ones, young warrior clones who embrace themselves when they were fighting the Axis.

Unleash the CIA to do its magic on the natons who misbehave. What magic? Don't ask. It's a secret.

Pump up the defense budget by a fixed annual percentage to show the world we mean business. This is a spiritual gesture, like a great national tithe to the Church of Deterrence.

Send out more flags, deploy more troops, get ready before the shooting starts. When the shooting does start, Americans will be there. Count on it.

If these Cold War policies seem comfortably familiar to American citizens, it is because they are the same policies which have reigned for 30 years -- first enunciated in 1947-48 by Harry Truman when Clark Clifford was a young man on his staff. The other day, Clark Clifford the elder was on Capitol Hill before a Senate committee, sounding the tocsin again, recalling the advance of Hilter in the 1930s and urging the nation to new vigilance against the Soviets in the Persian Gulf.

The coincidence reminded me of an old commencement speech somewhere in my files, an address delivered by Clark Clifford in 1978 at Loyola College. The senior wise man of Washington was explaining to the young audience how powerful is the memory of World War II and how it can blind national leaders.

"It is clear to me now, in retrospect, that we made a fundamental error in becoming involved. The tradegy is that the hard-won lessons we had learned in Europe, involving the Germans and then the Soviets, were misapplied in Southeast Asia.

"What we thought was a monopolistic conspiracy to spread communism and crush freedom in Southeast Asia turned out not to be so. As the picture clarified over time, we could recognize that the war in Vietnam was fundamentally a civil war and not naked aggression. The Soviet Union and Red China, instead of being allies, turned out to be adversaries.

"Our country's leaders, in their anxiety not to repeat the mistakes of the past, interpreted the struggle as requiring the intervention of the United States to prevent a much larger and more costly conflict."

I do not want to be unfair to Clifford. The Persian Gulf is not another Indochina; it is a quite different situation, many times more complicated and threatening to America. Still, I have to say it scares me when the Clark Cliffords of Washington reach for their Hilter memories and ask the rest of us to trust the clarity of their vision. Frankly, I think this generation of men still sees the world in terms of their own brave youth. But, alas, the world has changed.

The Persian Gulf of 1980 is not Vietnam of 1964 but it is not Western Europe of 1938 either. Clifford is smart enough to know that invoking Hilter summons forth in American policy makers -- not to mention the public -- a befogging collection of reflexes, the idealistic and the cynical impulses of World War II. If these reflexes are applied with America's usual gusto to the oil states of the Middle East, I predict pure disaster for us.

Perhaps it is not to soon to revive the tradition of "teach-ins" -- those rump seminars of the Sixties when, as Clifford acknowledges, young people on college campuses saw the realities of Vietnam years before the "picture clarified" for Washington policy makers like Clifford. What would they teach? I don't presume to know the answers, but I can think of some questions.

If the United States, as our leaders suggest, is rushing to the aid of small and helpless nations who are threatened by the Soviets, why do these small and helpless nations shrink from our embrace? Is it perhaps because these emerging nations fear American dominion nearly as much as the Soviet version?

What is the true nation of Islam emerging at this hour of history? We are all ignorant. Yet the simultaneous expression of reform and reaction in these Islamic rebellions seems at least as relevant to our future as the study of Soviet intentions.

Whose side are we on? The revival of "containment" as the regional strategy for the Middle East may comfort the old warriors but it tends to obliterate the real complexities. We are both friend and adversary on different levels to many of these nations, both protector and customer, potential enemy if they should attack Israel, potential ally if the Russians attack them. This is not a situation which can be explained by drawing red lines on maps.

How, indeed, do we support our friends? The Cold War approach, with few exceptions, has been to indulge them. We consistently support "free world" leaders in their excesses, blink at their crimes, ignore their political rivals. One can see the end result of that approach in Vietnam, Iran, Nicaragua. Are we now entering a phase where the same indulgent approach leads to a bad ending in Saudi Arabia or, for that matter, in Israel?

Hard questions, without simple answers. Our complicated struggle in the Persian Gulf is not nearly as satisfying as the great war to defeat fascism. That is what seems so scandalous about the revivalist atmosphere of Washington these says -- the easy way in which old men who should know better are opting for the absolutism of their youth.

I found another graduation speech in my files, alongside Clifford's, this one delivered last spring at Harvard by the author Theodore H. White. Before his fame as the premier storyteller of American politics, White wrote stirring history-as-it-happened from China and Europe, during those years of war and peacemaking. Like Clifford, he now sees that his generation was, in part, misled by its own great triumphs.

Last spring, he gave the Harvard seniors this warning:

"We came out of that war in 1945 with a sense of mastery, of controlover events, and with what one of my classmates, Arthur Schlesinger, a licensed historian, called 'The Politics of Hope.' There was an entire country ready to be remade, reshaped, reformed. If I sound my true note here for the first time, a note of melancholy, it is because I hope that you in your time do not suffer the same fate that befell us.

"That fate was to have everything we hoped for, struggled for, yearned for -- come about, and come true. And then to see those visions warped, distorted, and made grotesque in their execution."

The Greeks would understand the outlines of tragedy in this. Does a great nation, like a tragic hero, fall victim to its own triumphant nature, an overweening pride that blinds it to realities? Could that happen to us?

There is another good question for the "teach-ins."