I DON'T BLAME ordinary citizens for ignorance in this matter of the Red Menace of 1980. Life is too short to spend it reading Foreign Affairs and the other turgid journals where the Cold War is fought out in dense, bloodless theory. Normal people have better things to do.

I do blame ordinary citizens, though, for being so easily seduced by the new hysteria over national defense, a collective obsession of 1980 politics that is going to prove outrageously expensive and, if God isn't looking our for us, dangerous.

If Americans kept closer tab of their history, they would remember that they have been duped before by the cold warriors, stampeded by apocalyptic warnings that proved false. The Russians are coming. The Reds are superior. We are vulnerable. Armageddon is just around the corner. Unless, of course, we spend a trillion dollars. Yes, we intend to spend a trillion dollars on defense in the next five years.

Well, the Russians are not coming, folks, so keep your shirts on (if you have them left). The fundamental truth, in fact, is that they are weak, and getting weaker, and we are strong. We are not vulnerable. In the present season of martial music, that assertion marks one as irresponsible or, worse, craven. But I am confident that history is on my side.

A few years hence, I predict, the same learned theoreticians who are now exciting national fears will be writing thoughtful articles about how we misinterpreted and over-estimated to produce the born-again Cold War of 1980. Perhaps they will make discreet comparisons with the "missile gap" of 1960 when a similar hysteria, aroused by some of the same experts, proved phoney. Except that it resulted in the very real arms buildup of the Sixties.

Many Americans seem intimidated by this Cold War priesthood. They needn't be. Anyone of normal intelligence who can understand the stratgies and imponderables of pro football on Sunday afternoon can easily grasp the basics of the national security debates. Cold War theories are crude bits of whimsy compared with thoroughgoing war games of a Tom Landry or George Allen.

The difference is this: Those football coaches must test their "game plans" every Sunday afternoon. The nuclear thinkers have been indulged by history, never tested by the real thing, never forced to discover what a nuclear exchange would really be like. This should tell us something about how much theory to believe, for in the history of human warfare, particularly in the 20th century, new weapons have always altered war-making in horrible new ways that were not predicted beforehand. Consider the machine gun in World War I or aerial bombing in World War II.

If any earnest citizens wants to understand, the relevant information is not "top secret." Much of it has been printed in your daily newspaper. But first one has to cut through the general noise of alarm bells and define the three different arguments contained in this new wave of fright (next, one can go to the public library and read a few old articles, written in plain English).

"The Russians have us outnumbered in tanks and troops and planes -- they could sweep across the Rhine and reach the English Channel in a matter of days and we wouldn't be able to stop them."

This is the favorite spectre invoked by those arguing for a big buildup in conventional arms. Sometimes, these days, they substitute the Mideast for Western Europe. The argument regularly invokes deceitful comparisons -- our tanks vs. their tanks -- which even the densest senator must know is a phoney numbers game.

The U.S. military opted for the best and most expensive model of virtually every weapons system, including anti-tank wizardry; the Russian tank is crude and simple compared with our million-dollar electronic marvels. The Soviets, out of their own necessities, build on the cheap and build many more. Nobody, as far as I know, is seriously proposing to change our development strategy or even to match the Russians tank-for-tank, plane-for-plane. Yet they still play the numbers game because it sounds so scary (for a thorough account of what the trillion dollars will buy, see "5-Year Military Buildup to Cost U.S. $1 Trillion" by George Wilson, Post, May 19, 1980).

A resonable question about the crossing-the-Rhine scenario is why the Europeans, who would be the immediate victims, are less alarmed than we seem to be. Indeed, a reasonable citizen might ask: If we are headed toward disaster, why are our allies spending so much less on defense than we are (for comparisons, see "Allied Defense Costs: An Unequal Sharing of the Burden" by Michael Getler, Post, May 20, 1980).

One reason might be that nobody seriously believes the Russians are planning such an offensive or that they could pull it off without starting World War III, last in a series. The crossing-the-Rhine theories presume or pretend that neither the United States nor our allies would respond with the big one -- nuclear weapons. We are pledged to do so. It would be a rather desperate gamble for the Soviet leaders to roll the dice and find out if we meant it.

But why then do the Russians have all those tanks in Eastern Europe, if not to threaten us? Recent headlines provided one of the main answers -- to threaten their own satellites and keep them in line.

U.S. conventional forces do have serious and costly problems -- the replacement of worn-out equipment, inadequate maintenance, the technological escalation of weapons and their soaring price tags, the shortage of pilots and experienced technicians in the ranks. But more of these problems in a function of Soviet hegemony; none will be solved by scaring folks.

"For the next four or five years, the United States is in a dangerous window of vulnerability -- the Soviet Union could start a nuclear war and win it."

This is the notion that launched the $80 billion MX missile "racetrack" scheme, a proposal so dubious that even some conservative hawks oppose it (for the best scripture see "Assuring Strategic Stability in an Era of Detente" by Paul Nitze, Foreign Affairs, January 1976). The fear is that the Soviets now have enough megatonnage in place, ready to fire, to knock out all our land-based missiles in one strike. Though this is theoretically, true, no one should be surprised by the development; the Soviets have been building toward nuclear parity with us for the last decade. Anyway, the "window of vulnerability" theory depends on two very flimsy assumptions.

First, that the Soviet leaders, in some sort of crazy desperation, must be prepared for 100 million dead Russians if their gamble is wrong. This is what's known as "war-winning capability." The Soviet leaders are a brutish, hostile lot, but I don't believe they define 100 million dead comrades as "victory."

Second, that the U.S. president will surrender without a fight. Our land-based missiles are destroyed, tens of millions of Americans have been killed, radiation death is spreading across our land -- but the president decides not to retaliate with our thousands of protected bombs on submarines and bombers. Why? By the logic of vulnerability, he would conclude that it wasn't worth it, that more lives would be lost, ours and theirs, and we would wind up in total devastation. A humanitarian view.

Do you believe that? Nothing in American history suggests a precedent for surrender. Indeed, the history of modern warfare, in which many nations have faced similar choices, is filled with eloquent stories of leaders and peoples between devastation and surrender who chose terrible suffering before defeat and subjugation. Would Americans somehow be different? (For a lively version of how the Russians might see it, read "The Doomsday Debate" by Robert G. Kaiser and Walter Pincus, Outlook, Aug. 12, 1979).

The "vulnerability" issue evades the larger and now permanent reality -- both sides have overabundant nuclear arsenals, sufficiently protected from attack, to obliterate the other after absorbing a first strike, if necessary. Together, by 1985, we will have more than 35,000 warheads; we already have 14 billion tons of explosives, three tons each for every living mortal (for a dry-eyed description of the nuclear arms race, see "SALT: Straight Answers for Confused Citizens" by Richard Harwood, Outlook, June 10, 1979).

"We're not really talking about actual strengths and weaknesses -- we're talking about the perception of weakness. If it looks like Russia's arsenal is bigger than ours, it will influence world politics. Therefore, build we must."

This "perception of weakness" is the core anxiety, I believe, a spiritual malaise which infected cold warriors at the fall of Saigon. The argument is really a kind of self-fulfilling theology which lies beyond proof (for the best articulation, see "Testing Time for America" by James Schlesinger, Fortune, February 1976). To prevent the "perception of weakness," we should commit a fixed percentage of our growing national wealth to the military and argue later about how to spend it. This is roughly what the government is now trying to do, and it resembles the primitive rite of offering sacrifices at the alter of the war god.

What's more scandalous is this: The so-called "perception of weakness" is fundamentally wrong. The Soviet Union, as every scholar knows, is in deep trouble, at home and abroad, in the long run and in the immediate future. The scary image of Soviet hegemony, so familiar to American consumers, simply doesn't fit the facts.

The popular rebellion in Poland. The quagmire in Afghanistan. The Islamic reformation, which is much more threatening to the U.S.S.R. than to us because a growing portion of the Soviet population is Moselem. The new tactical nukes in Germany which threaten from the West. And, from the East, the new U.S. alliance with China.

The list goes on.While Americans never seem to see these as ominous for the Soviets leaders, the Soviet leaders do. Their perception is almost a perfect reverse mirror of the U.S. cold warriors' perception -- the Soviets see themselves encircled, threatened, endangered (for an excellent and up-to-date account, see "Soviets' Global Position Eroding" by Dusko Doder, Post, Sept. 11, 1980).

The long-run outlook for the Russians is even worse. The basic problem, after all the ideological rhetoric has been brushed aside, is simple -- their system doesn't work. The Soviet economy can't grow fast enough to buy all the military hardware and, at the same time, provide elementary consumer goods. It has to buy food from America. It has to borrow technology. Satellite nations like Poland have to borrow capital from Western bankers to stay afloat. Still, the Polish workers go on strike. That's why all those Russian tanks are in Eastern Europe.

These historic contradictions will become more intense in the 1980s because the Soviet population is changing in adverse ways. Because of abortions, a rising rate of infant mortality and a declining birth rate, the age group of young workers is shrinking as a proportion of the society -- and shifting, incidentally, away from the urban centers of industry and toward provincial minorities like the Moslems. None of this is expected to undo Lenin's revolution. But, at the very least, the Commies are facing hard times that make our difficulties seem benign and manageable. (see Peter Drucker's new book, "Managing in Turbulent Times, Harper and Row, 1980).

Everything I have said here has been said before, has been printed in newspapers and articles. Yet I would guess that much of it will be news to ordinary Americans. They don't pay close attention to the undramatic and tedious details, but they sit up and listen when someone cries "war."

I don't blame them for selective inattention, but I do think this: if Americans don't get smarter about themselves and the world, someday they are going to get hurt by what they don't know.