A CONCERNED CITIZEN would be forgiven for wondering what the hell is going on with the MX missile. We seem to have been batting it around for years without any resolution. Now -- is this possible? -- a definitive decision seems near. Either we are about to get the biggest missile we've ever built -- a missile that will carry 10 individually targetable hydrogen bombs up to 8,000 miles with pinpoint accuracy -- or we're going to give up on it.

The odyssey of the MX is a mind-numbing tale, and a lot of Americans must have tuned out many chapters ago. But the effort to keep up is rewarding, for by now this amounts to a fundamental lesson in the bizarre relationship between the United States and modern superweapons. The saga of the MX produces insights, even if it fails to produce a more secure America.

It is important to realize at the outset that different players in the MX drama look at the problem in very different ways. No one can understand this debate without knowing something about the participants' predilections. As sociologist Louis Wirth once wrote, the most important thing you need to know about a man is what he takes for granted.

The Air Force has long seen MX as a logical improvement in its arsenal -- a supermissile that gives the United States a capability that only the Soviets now have.

Since the 1950s the Air Force has tried to get as close as it can to a "first strike" capability -- which means the apparent ability to launch a first strike that would so debilitate the Russians that they would be reluctant even to try to respond. The Air Force also wants rockets with greater accuracy, so the Soviets will feel that even their most protected ("hardened") targets would be at risk in a war. Natural Air Force interest in a new model missile has kept the MX alive for years.

President Reagan and his allies are interested in the MX less for the specific military purposes the Air Force has in mind than for the impression it would make as part of a concerted buildup of U.S. military power. Politicians assume that nuclear weapons will never be used, but that they have to be acquired to preserve the peace. Reagan is a master of symbolism, and he clearly appreciates the symbolic significance of this missile monster. It's proof that the United States is serious about matching Soviet capabilities.

On the other hand, Reagan was determined not to use the MX plan that Jimmy Carter came up with -- for purely political reasons.

Others who support the idea of buying an MX don't subscribe to Reagan's view that the United States has fallen dangerously behind the Russians, but do agree on the importance of symbols in the arms race. This view was clearly stated by Lloyd N. Cutler, a "counselor" to President Reagan's MX commission and former legal counsel to President Carter.

"You've got to do something" to improve the U.S. arsenal in response to the Soviet buildup, Cutler said in an interview. Abandoning MX now "is just an irresolute thing to do," and would send exactly the wrong signal about American resolve to Moscow and to our allies.

Among the opponents of MX there are also many points of view. Advocates of a bilateral nuclear freeze argue that America does not need any new weapons, provided the Soviets stop acquiring new ones. Others will argue that new weapons programs now in view -- particularly the "Stealth" bomber that is supposed to be nearly invisible to Soviet radar, and an advanced submarine missile called Trident II that will be about as accurate and powerful as the MX -- are more than adequate to impress the Soviets and counter their buildup. Still others will argue that the latest idea for basing MXs -- putting them in the existing silos built for Minutemen intercontinental missiles in the 1960s -- is so wrongheaded that the missile isn't worth the $15 billion to $20 billion it will cost.

But behind these many points of view is one basic question: How can we best preserve nuclear peace while protecting American interests?

The back-and-forth about symbolism, national will and so on only obscures the heart of the matter, which is "deterrence." Deterrence is a simple idea: It means the ability to convince the other guy that launching a nuclear attack would be suicidal. The Soviets are deterred from attacking us because they know for certain that if they did, their own country would be destroyed.

The push for an MX missile has always been justified on the ground that it would enhance deterrence. But does deterrence need enhancing? Are we in any danger that the Russians might conclude that they could attack -- or threaten to -- without risking the survival of the Soviet Union?

Comes now the famous "window of vulnerability." Future historians will marvel at this one. After knocking around in strategic journals for years, it came into prominence in the late '70s, promoted by hardliners who were looking for arguments against the SALT II treaty negotiated by Jimmy Carter. According to the drafty-window theory, when the Soviets deployed enough accurate warheads on their best land-based missiles to be able to target at least two of them against every American rocket that sits in silos in the Midwest and West (that is, about one fourth of America's total arsenal), the United States would become vulnerable to a lightening Soviet attack that could wipe out those American ICBMs. After such an attack, the American president would face a horrible dilemma: to strike back, knowing this would then bring a follow-up Soviet attack on all American cities, or to cry uncle.

Think about that for a moment. The drafty-window crowd was arguing that an American president would accept an attack of at least 2,000 hydrogen bombs on U.S. territory and respond byycrying uncle, even though he retained three-fourths of the American nuclear arsenal -- enough weapons on bombers and submarines to reduce the Soviet Union to radiant rubble. They were also arguing that some Soviet leadership would risk the survival of the U.S.S.R. on the calculation that this is what would happen.

The theory of the window of vulnerability had more wrong with it than that. It also assumed that the Soviets would risk their country's survival on an attack that had never been -- could never be -- practiced, and that would require the most stunning technological coordination and the perfect performance of hundreds of Soviet missiles. As former Secretary of Defense James Schlesinger -- another counselor to the MX commission -- put it last week, "The Soviets can never have a high degree of confidence" that such an attack would work. Never.

But the window of vulnerability had a wonderful quality for the strategic thinkers. It was "theoretically possible," and for those who accept the responsibility for preserving America against all nuclear dangers, no matter how far-fetched, that's cause enough for concern. Moreover, this theoretical Soviet advantage created the appearance -- the "perception," to use the strategists' favorite word -- that the United States might be at a disadvantage. In some future, unspecified crisis, the Soviets might exploit this appearance to "blackmail" the United States. (Here again you need an American president who will cry uncle -- who will succumb to blackmail even though he retains a devastating retaliatory arsenal.)

Anyhow, the window of vulnerability became the issue of "Minuteman vulnerability." Minuteman is the solid-fueled intercontinental missile that we began deploying in the '60s. It's a formidable weapon, and we now have 1,000 of them. But if it was theoretically becoming "vulnerable," it could no longer be relied upon. This became the main rationale for the MX.

The rationale part depended not on the missile itself, but on where it was put -- on its "basing mode." The Air Force probably just wanted the MX for its destructive power, and particularly for its ability to destroy Soviet missiles inside their silos, but the politicians needed to be able to claim it was invulnerable to justify spending billions on MX. So the idea was to find a way to hide it from the Russians. The Pentagon came up with dozens of ideas for hiding it -- underground trenches, airplanes, racetracks, dense packs and so on. Unfortunately, none could pass both political and technological muster.

Comes now the latest Reagan commission, a blue-ribbon panel formed to save the MX after Congress voted against the administration's last basing idea, the dense pack deployment (lots of missiles clustered close together so that attacking Soviet missiles would destroy each other, not our MXs).

The important fact, apparently undisputed by any participant, is that the commission was formed to save the MX. Conversations with several commission members and counselors confirm that the group began its work with a common sense that it had to find a new, politically acceptable rationale for the weapon.

Why? Because members of the commission shared the assumption that it would be politically and diplomatically disastrous to abandon the MX at this late stage, after spending $5 billion on it and talking about it for so long.

Harold Brown, Jimmy Carter's secretary of defense and a counselor to the commission, put it with great clarity (and not a little absurdity) last week. If the United States fails to deploy the MX, Brown said, "it would be the first nuclear strategic defeat for any country since World War II." Thus has symbolic politics assumed gargantuan proportions in this debate. You almost expect to hear Henry Kissinger explain again why we must keep investing in the Vietnam war, since we've put so much into it already.

Starting with that perception of a symbolic imperative, the commission set about re-rationalizing MX. It recommended putting 100 MXs into existing silos now filled with older Minutemen missiles. It recommended redirecting the entire course of arms control negotiations in a way that would undermine the SALT II treaty and President Reagan's initial position in the current negotiations. It recommended constructing a new, mobile missile that could scurry around the countryside, thus confounding Soviet targeters.

It is understandable that men like Harold Brown and Gen. Brent Scowcroft, chairman of the MX commission, believe that it is now too late -- for symbolic political reasons -- to abandon the MX. It is understandable that others will agree, perhaps even including a majority in Congress. Those who do agree will find the commission's report just what the doctor ordered.

But there is certainly another way of looking at it. If the commission's report succeeds as a political document, it flunks as a piece of analysis. Judged on its internal merits, it is a plausible fraud.

The Scowcroft commission decided, mercifully, to bury the window of vulnerability -- it had to, in order to recommend putting 100 MXs into those theoretically vulnerable Minuteman silos in Montana and North Dakota. You can't recommend spending $15 billion on a turkey. So the report contains some good analysis explaining why the Soviets won't try a sneak attack on all our land- based forces.

But wait! The commission also resurrects the theory of vulnerability to justify the construction of a new "midgetman" missile, a smallish rocket that could be transported about on a blast- resistent truck of some kind so the Russians couldn't target it. This would "permit flexibility in basing for better long-term survivability."

Members of the commission apparently realized there's a contradiction here, so they threw in another argument for the midgetman -- it would be useful in case the Soviets figure out how to locate and attack our missile submarines at sea, which are the really invulnerable part of our forces. Is this remotely likely? No, but it is theoretically possible. Remember that one? You might notice that neither of these arguments in favor of midgetmparan offers any support whatsoever for deploying MXs in Minuteman silos, which is the commission's main recommendation. You may notice that, but the commission apparently didn't.

The commission also says it would be desirable to have a mobile little missile "to reduce target value." This strategists' lingo means it would be desirable not to put so many eggs in one basket that in a crisis, the Russians might be unable to resist the temptation to attack a juicy basket. A lot of little rockets carrying one warhead each offer a less appealing target than a few giant ones each carrying 10 bombs.

Good thinking. But the commission suspended it before coming to its recommendation to put MXs into Minuteman silos. That's because MXs in Minuteman silos are the juiciest individual targets the United States has ever offered to Soviet missile marksmen.

This matter of creating irresistible targets worries a lot of experts, including some Air Force commanders. Their concern is that the existence of juicy targets in vulnerable holes would tend to put more of a hair-trigger on both nations' arsenals.

A reporter asked Scrowcroft and his colleagues about this at their press conference last week. Here, according to the transcript, is how they answered:

Gen. Scowcroft: "I don't know -- Jim, why don't you comment on that."

James Woolsey (undersecretary of the Navy in the Carter administration): "Let Jim --"

James Schlesinger: "You wanted that --"

Woolsey: "Go ahead, go ahead."

Schlesinger: "All yours."

Scowcroft: "Trying to share the wealth here (laughter)."

At which point Woolsey jumped back in and changed the subject. The question was never answered.

There are some other problems with the MX commission's reasoning. It blithely declares, for example, that deploying 100 MXs would "remove" or "neutralize" the Soviet advantage in super accurate land-based missiles, though Moscow would still have five times as many warheads as us in this category. Questioned about this assertion, James Woolsey backed away from the commission terminology. "Redress" would be a better word than "remove" or "neutralize," he said. Woolsey was the principal draftsman of the report.

Imagine a Soviet leader's reaction to American deployment of 100 MXs. Is he likely to say, "The Americans are only going to let us have a 5-to-1 advantage in supermissiles -- we can't stand for it!"? Fat chance.

It seems much more likely that the Soviets have understood from the beginning that all arguments based on the theory of the vulnerability of land-based missiles are silly. Does it make sense that the Soviets would keep putting so much money and effort into that part of their missile arsenal if they expected that the Americans could "neutralize" it? No, the Russians understand better than we do that no sane commander will ever voluntarily risk a full-scale attack in the hope the other side won't retaliate.

The line of reasoning employed by the Scowcroft commission effectively turns over to the Kremlin the right to decide on the shape and size of American nuclear forces. The commission acknowledges this, albeit indirectly, by adopting the theory that we must be able to match every apparent Soviet capability, whether or not that capability appears to have genuine utility as a deterrent or in war.

Here's how the commission put it: "If comparative military trends were to point toward their (the Soviets) becoming superior to the West in each of a number of military areas, they might consider themselves able to raise the risks in a crisis in a manner that could not be matched."

What do those last words mean? Gibberish. If we have to match every adversary's ability to increase the danger of a crisis, then we have totally lost control over our own affairs. The real aim has to be to acquire enough weapons to assure that deterrence still works. Deterrence is all that will save us from nuclear war, and the definition of deterrence cannot change every time the Russians add another 100 warheads.

Well, thapart isn't universally accepted. James Woolsey thinks that "delays in deployment (of new weapons systems) indirectly weaken your deterrent somewhat." We have to keep deploying new weapons. Or only a continuing arms race provides safety.

That may sound nutty, but it has actually been the governing ethos of American policy for decades. Is it finally time to stop?

Freeze advocates say yes, but you don't have to favor a freeze to reject the recommendations of the Scowcroft commission. There are plausible alternatives to its program of MX deployments, midgetman development and a whole new approach to negotiating with the Russians. The alternatives are both symbolic and tangible.

Symbolically, the notion that we have failed to respond to the Soviet buildup is largely a figment of the American imagination. To believe that we have done nothing in recent years, all you have to ignore is the Mark 12A warhead that has made 300 Minutemen almost as accurate as the MX will be; the new cruise missile technology, which promises to make Soviet territory vulnerable to bomber attack for years to come; the B1 bomber now in production and the radar-evading Stealth in development; the deployment of the new submarine-based supermissile and its giant launching pad, the Trident I; the decision to deploy new missiles in Europe that can strike Soviet territory; the construction of three new nuclear-powerd carriers whose fighter-bombers can strike Soviet territory; and the Trident II missile which promises to give the United States the power and accuracy of the MX by the end of this decade.

A president who found the voice to boast of all those accomplishments instead of publicly declaring American inferiority could reverse the symbolic political equation with alacrity.

More tangibly, there is a perfectly plausible program that will meet any conceivable Soviet threat, provide inducements for Soviet negotiators, and protect American vital interests. It would consist of preserving the Minuteman force of land-based missiles (which would require modernizing them as time passes); proceeding with development of the Trident II missile while emphasizing to the Soviets that it can be bought off with the right kind of arms control deal; proceeding with development and deployment of B1s, cruise missiles and Stealth bombers; and perhaps adopting one of the Scowcroft commission's minor proposals by investing now in development of a new mini-submarine that could carry Trident missiles.

All those steps are expensive and would show how tough we are. All of them can be justified without reverting to political mumbo-jumbo.