WANTED: An invulnerable, permanent home for at least 100 of the Air Force's giant, 92-inch wide, 71-foot tall, new MX intercontinental ballistic missiles. You know -- the ones we must have to prevent the Soviet Union from attacking us.

Probably tomorrow, President Reagan will make his latest contribution to a saga that has now spanned 10 years and four administrations, a saga that would be simply hilarious if it weren't also serious. In each chapter of the saga, the administration of the day is searching for a safe place to put these missiles, whose 1,000 highly accurate warheads, each more than 10 times as powerful as the Hiroshima bomb, are supposed to be the needed answer to the Soviets' missile force.

Reagan's latest attempt to find a home for the MX comes 13 months after the same Reagan announced on national television that "after one of the most complex, thorough and carefully conducted processes in memory" he had come up with a program for the MX.

The notions put forward that day in October 1981 for MX basing lasted well into the summer of 1982, but not much longer. The next chapter will unfold under the name of "Dense-Pack."

If there were not serious defense, diplomatic and domestic policy questions involved in this endless saga, the whole process could be seen as a bizarre satire on the Pentagon as a political and economic playground. The stars of the satire have changed with each change of administration, but the show has gone on year after year. The Reagan players don't seem to deserve any more ridicule than any of their predecessors, they just happen to be the current occupants of the major roles.

If you remember (and it would hardly be surprising if you don't), on Oct. 2, 1981, the president, with Secretary of Defense Caspar W. Weinberger by his side, went on national television to announce his plan "to revitalize our strategic forces and maintain America's ability to keep the peace well into the next century." It included building the B-1 bomber and developing a new Trident II submarine-launched missile. But the centerpiece of the program was the president's decision to go ahead with building 100 new MX missiles, placing the first 40 in existing missile silos that would be made much stronger -- and thus less vulnerable to Soviet attack -- by the addition of huge quantities of concrete and steel. The administration would study three other schemes for deploying the other 60 MXs, announcing a decision later. So Reagan said last year.

The three options under study, Reagan said then, were deep underground basing, airborne basing or deceptive basing in silos, perhaps protected by a new antiballistic missile system.

What we didn't know at that moment but do know today, thanks to this newspaper's White House correspondent Lou Cannon, and his book "Reagan," is how the president reached that decision. According to Cannon's account, Weinberger had drafted the decision shortly before it was announced.

Weinberger made his decision at the last minute, after rejecting the advice of both his own expert panel and the Joint Chiefs of Staff, apparently in the hope that something better would turn up. The most embarrassing, but perhaps most illustrative, portion of Cannon's history of that moment is that Weinberger sold the nation's commander-in- chief on his proposal, not by explaining it in any detail, but rather by showing the president a cartoon from a newspaper which made fun of former President Jimmy Carter's plan for MX basing. That was the " shell game" idea -- building 4,600 shelters for MXs, and shuttling 200 missiles from shelter to shelter to fool Soviet targeters.

The cartoon depicted a Carter-like figure showing three nutshells on a table to a Brezhnev-like figure, asking him to guess where the missiles were hidden. In the next panel the Brezhnev figure crushed all three.

"Reagan chuckled," Cannon writes, after explaining that the president was tired that afternoon, "and approved the Weinberger plan" without any explanation of it.

This certainly was not the first time a president has blindly accepted a defense plan from a trusted cabinet member. What's disturbing about this one is that Weinberger was, as one military man put it recently, "flying on his own." The defense secretary had ruled out the Carter plan and any other multiple basing scheme for political reasons, though he never expressed it just that way.

He clearly didn't want to appear to be adopting any idea with a Carter label on it. Moreover, Weinberger did not want to inflame the Nevada constituents of Reagan's close friend Sen. Paul Laxalt (R-Nev.), who would have to give up a large part of their state to accommodate the MX shelters envisaged in the shell-game scheme. Laxalt spoke for popular sentiment in Nevada when he came out against the shell-game idea.

As Cannon gracefully put it, Reagan's tough stand during the presidential campaign for strengthening the U.S. ICBM force "faded softly into the Nevada sunset."

Within four months of the October 1981 announcement, Reagan's MX decision was in shambles. It became clear there was no way you could satisfactorily "harden" existing silos with concrete and steel, and the three "promising" permanent basing ideas, all of which had been explored by earlier administrations, were found wanting again.

Sometime during the summer, the Air Force, with encouragement from the White House, resurrected the idea of packing MX silos close together on the theory that if the Russians tried to knock out all 100 silos, the radiation, debris, explosive pressure and heat from the first warheads that landed would do as much harm to the remaining incoming warheads as it did to the first few silos that would be hit. In the lingo of the nuclear weapons community, this theory was termed "fratricide" -- in other words, the first H-bombs to explode would kill off their brothers raining down subsequently.

The new basing plan was given the name "Dense-Pack" and various studies were undertaken to see if it could be said to work. In the succeeding months, "Dense-Pack" gained a predictable following, led by the Air Force, whose overriding interest is to get the MX.

But Weinberger has had his doubts, as have many of the experts. It is now part of this saga that every new idea produces a new set of critics. Dr. Charles Townes, the chairman of Weinberger's panel of scientific experts, warned that the new plan offered no solution for the long run -- if the Soviets build more warheads, "Dense-Pack" will become vulnerable.

One clever opponent came up with a study that showed that at best, "Dense-Pack" could only survive repeated Soviet attacks for four hours, if the Soviets timed their shots carefully. Thus you were spending $20 billion or more for just four hours of security.

Perhaps the final beauty of Dense-Pack for its proponents is that no one can prove that it won't work. There is no way you can test what the "fratricide" effect will be when one nuclear warhead explodes on the surface of the earth as another comes down through the sky to explode.

This logic can be taken another step. The rationale behind all our nuclear forces is "deterrence" -- to make the Soviets believe they can't get away with attacking our missiles without theirs being attacked in return. So the purpose of any MX basing plan is to come up with something that we can tell the Russians will work. Naturally, then, an American government will say the system works. Whether it really will makes no difference.

Confused? Well, you are supposed to be if you are a normal individual and not a nuclear strategy expert. Simple logic has no obvious place in considerations of the MX problem.

More typical is last-minute improvisation. In a delightful new book entitled, "Super Weapon, The Making of MX," author John Edwards provides exquisite detail on how the Carter administration decided to place 200 MX missiles among 4,600 horizontal shelters that looked like cement garages.

In 1978, according to Edwards' chronicle, Defense Secretary Harold Brown favored building an MX and basing it in a "shell- game" system. (Brown favored a "vertical shelters" shell game over the later "racetrack" shell game, but that's another story.) Zbigniew Brzezinski proposed putting the missiles on mobile trucks. And President Carter toyed with the idea of building no new missile while studying the idea of launching our force of Minuteman missiles when it was clear our force was under attack. (If we've launched them, the Soviets can't blow them up, according to this line of thinking.)

Eventually, all the key players in the Carter administration changed their minds.

Back in 1981, the Air Force put together a wall chart that illustrated 27 different basing ideas that had seriously been explored and rejected for the MX. Among the more original were basing it in midocean, underwater (there was fear someone might steal it); and putting in on a large flying boat -- a cousin of Howard Hughes's spruce goose.

Whatever President Reagan announces tomorrow, the MX saga won't end there. Congress retains the last word on the missile's future, and with any luck, Congress will move this debate from the arcane and often irrelevant world of the nuclear strategists into the realm of common sense.

Common sense will lead to the conclusion that we don't need an MX missile. A little history explains why.

Back in 1945, according to Manhattan project archieves, when a distinguished group of government officials, scientists and military men (Henry Stimson, Gen. George C. Marshall, J. Robert Oppenheimer, James B. Conant and others) decided on the targets for the first atomic bombs, they selected two Japanese cities where military installations lay close to residential areas. Their reasoning was simple -- and brutal.

They considered the atomic bomb a weapon of terror, designed to frighten a country into surrender with the threat of possible extermination. But because these were civilized men, they liked the idea of "targeting" the military installations at Hiroshima and Nagasaki to cloak their uncivilized aim of mass human destruction.

It is too easy to forget that just two small atomic bombs -- less than one-tenth the size of each of those 10 hydrogen-bomb warheads on top of just one MX -- killed 200,000 Japanese and injured another 130,000.

If we realize that mass destruction is the real mission of these weapons, then it becomes harder to explain why -- when we already have 7,500 warheads on land-and sea- based missiles -- we really need 1,000 more. The strategists reply that we need them to attack "military targets" like thousands of missile silos on U.S. and Soviet territory. But if "the balloon goes up," to use one of the many horror-disguising euphemisms of the strategists, the first wave of missiles may be aimed at missiles on the other side, but their principal effect will be to kill millions of people.

And if there is a real deterrent that would stop the Soviets from attacking, it is that their cities and people would face destruction, not that their remaining missiles would be threatened. This is the mutual assured destruction theory of Defense Secretary Robert S. McNamara, that cutely and disparagingly has been nicknamed MAD.

That was the theory behind the first atomic bomb attacks and despite the strategists' euphemisms, it would be the theory of any other. Destruction must also be the main fear of any attacker.

Despite all the hundreds of thousands of pages that have been devoted over the past 37 years to describing tactics and strategies for basing and using nuclear weapons, any Russian or American leaderrwho pushes the button will know that the first strike is also going to be the last. The strategists' contrary nonsense has given us thousands of missiles, bombs and other devices, but it has not given us any security.

Nuclear weapons remain what they were in 1945, when they were first used -- weapons of terror. And that is how we should talk of them.