WHAT JONATHAN SCHELL calls "the nuclear predicament of mankind," the total impact of a major nuclear war, has now, for the first time, been analyzed systematically as a coherent whole, in the full range of its presently recognized consequences. Schell spent five years interviewing groups of scientists in various fields of study where the effects of nuclear war are being explored. Those lines of inquiry included the possible effects on human beings physically and psychologically, on the biosphere and the life support system in which they live, on the economy by which their needs are met, and on the organized society which brought civilization to its present high level. He found that these separate effects of a nuclear war reinforced each other to a degree not appreciated even by the experts; that the many different aspects of a nuclear war would interact on each other to such an extent that the total damage would be far worse than most of us had thought.

"Everything would affect everything else," he writes. The result would be a true "holocaust"--a word from both Latin and Greek which indicates completeness of destruction. In classic times it meant destruction by fire; today it would be nuclear fire like that of the sun.

Schell's work should shift the focus of public debate on nuclear weapons from the strategies of war to the highest levels of human concern. One is the destruction of civilization. Another is the likely degree of damage to the entire human species and of its ability to survive and recover. What would intense radiation do to genetic inheritance? Could lethal amounts of the sun's ultraviolet radiation break through a damaged ozone layer around the earth, and seriously affect the human race? Many such questions are being asked and studied by scientists. There are no clear answers yet, but the emerging picture of nuclear war is awesome.

The publication of Schell's work comes in good time. Up to now the American democracy has not taken part in many decisions that have made nuclear war an intimate aspect of its daily life. The public had nothing to do with President Truman's decision to build a thermonuclear arsenal or with John Foster Dulles' decision to threaten the Soviet Union "with massive retaliation at a time and place of our own choosing" if we objected to Soviet actions. These were decisions made inside the White House by the commander-in- chief. It was not the American people who made up the nonexistent bomber and missile gaps and geared up massive military programs in response to them, or failed to alter their course when it was ultimately discovered that the Soviet Union had no comparable programs. These imaginations and responses were the creations of scientists, military men, high administration officials, and important members of Congress. The bulk of the American people hardly know even now what was done in their name. They, in Schell's words, have "declined on the whole to think about the immeasurable importance of nuclear weapons. We have thus far failed to fashion, or to discover within ourselves, an emotional or intellectual or political response to them . . . Only very recently have there been signs . . . that public opinion has been stirring awake." These stirrings began as a grass- roots phenomenon, but state legislatures and Congress are now becoming involved, and voluntary organizations concerned with stopping the nuclear arms race are starting to pull together.

No one should underestimate the national trial by fire of debate which lies ahead. Since World War II the concept of preparation for war, in the hope that it will keep the peace, has become deeply entrenched in the American mind and in the government establishment.

Most Americans forget that the present defense policy of the United States is not a product of the Reagan administration. It goes back 35 years to the time just after the defeat of Hitler. The American leadership at that time decided that the nation had made a terrible mistake by not rearming when the Nazis and the other Axis powers became aggressors. Being unwilling to fight, the United States and Britain had remained unarmed and backed away from confrontation when Japan invaded China, Mussolini seized Ethiopia, Franco destroyed the Spanish Republic with help from Germany, and Hitler marched into the Rhineland, then into Austria, then the German-speaking part of Czechoslovakia. By then Hitler had acquired a contempt for the weakling Western powers. He invaded Poland and World War II broke loose.

So when Hitler was gone and the United States turned to face Stalin, it abandoned its earlier mood of isolation and remained fully committed to defend the peace so recently won. That seemed the necessary thing to do at the time. But a quarter of a century later, both the United States and the Soviet Union were strongly armed with nuclear missiles. The nature of large-scale conflict between what are now called superpowers had radically changed, as Schell clearly and inexorably explains. The price of victory, which was the goal of earlier wars fought with conventional weapons, and was the means of threatening an aggressor with punishment, was now virtually impossible. Nuclear conflicts bore no relation to war with conventional weapons. Most everyone knew what it meant to win a conventional war. The victor overpowered the enemy's forces, invaded his territory, dictated terms of surrender, occupied the country and especially the capital city, disarmed and took control of the defeated government and people. How could these events take place after mutual nuclear attacks? Both the United States and the Soviet Union would be in a state of extreme physical and psychological shock.

Suppose that a surviving American political or military leader tried to act like a victor. How could he tear surviving manpower away from the home front with its desperate need for all kinds of rescue and reconstruction? Where would he find the means to assemble enough of an armed force and equipment and transport it across the world to a country drenched with radiation and leveled into chaos? How would it establish control? Obviously neither side could accomplish the purposes of war or enjoy its traditional fruits.

In the past there was time for new technologies to be developed and for the armed services to master their use. There won't be time to discover from experience that nuclear wars aren't "winnable." The game will be over. The public will have had no adequate opportunity to learn what seven presidents, Republicans and Democrats alike, didn't care to emphasize: that in an arms race the concept of deterrence slips easily into being prepared for war and willing to fight it. They didn't want to frighten the public into protesting against nuclear war, and thereby destroy the credibility of deterrence.

This is a problem of some subtlety in a democratic country where the public is entitled to decide its own fate. One can only sympathize with the leadership in Washington which for decades has been caught in the dilemma of how much to inform the public--or even to face the questions themselves, for example, about the possibility of deterrence breaking down in the midst of tensions created by an intensified nuclear arms race. One can equally sympathize with the American public, now that citizens are beginning to ask what cost they are expected to be ready to pay, by assuming the risk of voting for the continued arms race. And what of the billions of people in the nonbelligerent nations whose futures are also put in jeopardy?

Will the forthcoming debate run to extremes in terms of hawk or dove, of panic or willingness to die a national death? Can it be resolved on terrain where the issue is neither militarist nor pacifist? Will it bring about rational and persistent negotiation with the Russians over arms limitation and political stability--as befits defenders of both life and civilization on both sides?

These are questions that a widespread reading of Schell, and waves of resolutions in Congress and state legislatures, are likely to precipitate. It's a good idea to think them through and get ready for a reasoning debate.

There are a few useful cautions for the willing reader.

Schell is not always easy to read, and it will help to decide in advance not to be annoyed by repetitions. There is a rich reward for patience and persistence on the part of the reader. The writing ranges from exquisite poetic passages to those unnecessarily complicated. One occasionally wonders if he had an editor. The material is densely packed. The book is continually lighted by powerfully logical and brilliantly written passages.

The reader will not find a blueprint of what the public should decide to do. Nor does Schell lay out the political options with their pros and cons. In fact he avoids considering the many arguments and mistakes that brought the world to the brink that he explores. My own inclination would be to explore the human misunderstandings that got us here, in hopes of doing better. Schell is content for his purposes to confine himself to a major conclusion: the need for creating institutions that are capable of settling conflicts by political means instead of by war. He wants the world to understand its predicament so that it can focus on solutions.

Finally, the reader will soon discover that Schell thinks we must face a possibility that the human race could become extinct as a result of nuclear war. It is important to see how he qualifies this concern. "To say that this is a certainty," he writes, "would, of course, be a misrepresentation-- just as it would be a misrepresentation that extinction can be ruled out . . . we are compelled to admit that there maybe a holocaust, . . . that the global efects . . . may be severe, that the ecosphere may suffer catastrophic breakdown, and that our species may be extinguished. We are left with uncertainty, and are forced to make our decisions in a state of uncertainty . . .

"Once we learn that a holocaust might lead to extinction," Schell concludes, "we have no right to gamble because if we lose, the game will be over and neither we nor anyone else will ever get another chance . . . Our procedure, then, should be not to insist on a precision (of research and evidence) that is beyond our grasp, but to inquire into the rough probabilities of various results, insofar as we can judge them, and then ask ourselves what our political responsibilites are, in the light of these probabilities."

These careful qualifications, neither predicting nor denying the possibility of extinction, should be kept in mind by the reader. For Schell spends many persuasive pages on the responsibility of the living to safeguard the privilege of birth to the unborn, and he might seem in those pages to be accepting the likelihood of the end of mankind--whereas he is not, as the above quotations show.

There could be a diverting argument over a misunderstanding of what he wishes to convey in this one aspect of the book. It could distract the public from the merits of Schell's work as a whole, from his important contribution to our understanding. It is of some relevance to report, therefore, that a group of scientists who specialize in the various effects of nuclear war met recently to discuss what he said about the possible end of the human species. They generally agreed that research on this question is still in an early stage, and that there is no present evidence that would cause them to expect the end of mankind, but that one can't be certain. Furthermore, the rest of Schell's arguments, which they accepted, gave them "far more than enough reasons to be greatly disturbed," as one of them put it. The others agreed.