AFTER THE 1976 military coup in Argentina, the tactics of the death squads changed. Instead of leaving bullet-ridden bodies along the roadsides, or charred corpses in burnt-out cars, or mutilated human remains on garbage dumps, they left only paralyzing fear and agonizing uncertainty. People simply disappeared. The new death squads left no bodies behind them.

When Jacobo Timerman, Argentina's best-known and most controversial journalist, was seized on a raw April morning in a dawn raid on his apartment in central Buenos Aires by 20 armed men in civilian clothes who said they were from the Tenth Army Brigade, several thousand people had already vanished, never to be heard of again. That was just a year after the coup of March 24, 1976. Today there are about 6,000 documented cases of disappearances, including at least 61 journalists. In many cases there is strong evidence to suggest that they were abducted by the Argentine government's own security forces. The most conservative estimate by human rights organizations places the number of people claimed by the security forces' "Night and Fog" operations at around 10,000. Nobody has dared claim that they were all left-wing terrorists.

Timerman is one of the few who came back from the Argentine netherworld and is the first to give testimony in book form of his ordeal as a nonperson -- a prisoner without a name in a cell without a number. One of the reasons -- perhaps the compelling reason -- why Timerman was incarcerated for two long years, after a military tribunal found that it could bring no charges against him, was fear of what he might reveal. When I as a fellow journalist pressed for his release, I was asked by military officers again and again, "What will he say if we free him?"

Now they know.

When he was thrown out of the car by his kidnappers and lay on the ground in the first of the three clandestine prisons where he was held, as well as in two actual jails, during his first year of captivity, he was subjected to a simulated execution. Then followed barbaric torture sessions, insensate cruelty, persistent humiliation and the ever-present shadow of death.

One of his interrogators during this first encounter with Susan, the name given to the electric torture machine, tells him: "Only God gives and takes life. But God is busy elsewhere, and we're the ones who undertake this task in Argentina." He notices that one of his guards is wearing his gold Rolex watch; another lights a cigarette with his wife's Dupont lighter. In another clandestine prison, Timerman meets the former publisher of Argentina's leding financial daily, Rafael Perrota, who has been kidnapped for ransom. In this manner the death squads fund themselves. They also have three beautiful girls in their early twenties, who have been accused of terrorism but are used to satisfy the guards' sexual appetites. "They've been tortured, violated and gradually corrupted, out of that need a prisoner experiences of building some sort of life that encompasses a measure of hope . . . some sort of reality besides the flight into madness or suicide."

One of the girls is the chief's lover, and she has managed to get permission for her father to come and live in the prison. He shares his daughter's cell and even becomes a friend of her lover. He does the shopping and brings back an orange for Timerman. He makes himself useful, is an electric engineer, and looks after maintenance. Timerman is undergoing torture, his body jack-knifing as electric shocks are applied. "Suddenly a hysterical voice begins shouting a single word: 'Jew . . .Jew . . .Jew!'" The torturers become as excited as children, circling him and clapping hands. "Now they're really amused, and burst into laughter. Someone tries a variation while still clapping hands: 'Clipped prick . . . clipped prick.' Whereupon they begin alternating while clapping their hands: 'Jew . . . Clipped prick . . . Jew . . .Clipped prick . . .' It seems they're no longer angry, merely having a good time."

The central message of this haunting, disturbing book is Timerman's conviction that his guilt in the minds of the Nazi clique which initially kidnapped him was to be a Jew. "We were not all Jews in those hidden prisons. Many of us were. We Jews continued to be Jews, and being Jewish was a category of guilt, even when we were declared innocent of other offenses and absolved of other crimes." This is the pain that sears through the book, the memory of "the shout with which my interrogators used to insult me when they were really furious -- Jew!"

It is Timerman's need to expose the horror of his discovery that Nazism was alive and well and as virulently anti-Semitic as ever in Argentina in the late '70s that makes his sentences, beautifully shaped from the Spanish by a sensitive wordsmith and translator, Toby Talbot, scream from the page: "During a visit from the Israeli leader Yigal Allon, while I was under house arrest in Buenos Aires, I told him that I had not been humiliated by torture, by electric shocks on my genitals, but had been profoundly humiliated by the silent complicity of Jewish leaders. My incarceration and torture were a personal tragedy, but nothing more, for in view of the sort of journalism I practiced, the possibility of my arrest and assassination fit into the rules of the game. Whereas the panic of Argentine Jewish leaders constituted a nightmare within the tragedy. And it was that nightmare that agonized me and kept me awake."

Timerman cannot forget the screams of a woman under torture in the dingy kitchen next to his cell telling her tormentors that she is a Catholic, not a Jew and that her name is German. It is a last line of defense unavailable to a Jew, he notes wryly. And so Timerman believes that "perhaps the Holocaust is in a way already occurring, as if the seeds were already planted." The scope is not as monstrous as it was in Germany, but: "Must all anti-Semitism wind up in soap?" Timerman believes that the evil that he saw and suffered is the same, except in scale. There is pleasure in torturing Jews and "Jewish girls were violated twice as often as other girls." And -- a stunner this -- when, over a year before his arrest, he is disputing with a navy officer the Nazi tactics being used by the security forces, Timerman, then a man of consequence, creator and publisher of La Opinion, the Le Monde of the Spanish-speaking world, is told: "Hitler lost the war. We will win."

Timerman presents an admittedly, understandably, obsessive view of a regime some other people see as "moderately repressive." In my short time in two prisons (three cells without numbers, but I never lost my name), I saw the huge swastika the police had painted on the wall of the entrance hall to the top-security cells in the Federal Police Security Superintendency. The political police operate from this building. I, too, heard the screams of people being tortured and was not surprised that the military should have seen nothing amiss in its initials (the same in English and Spanish): The SS. My incarceration was brief but humiliating. From personal experience as well as conversations with other people who have entered the netherworld of torture with pictures of Hitler looking down from the walls and have emerged, I can vouch for Timerman's accuracy. His descriptions of clandestine and actual prison life are beautifully honest and very moving. Practical too, with much advice on how to survive and resist the twin temptations of madness or suicide, when undergoing solitary confinement.

I have a different view of the Argentine military. The moderates have been in nominal power now for five years but have yet to muster the courage to purge their ranks of the obscene and degraded individuals responsible for torture and arbitrary murder. To save their honor they will have to come clean about the disappearances. Was it a policy or a horrendous mistake? Who was responsible for making the decision that gave some men the power of life and death (and drove some of them mad in the process)? When will that individual, or those individuals, accept responsibility for that truly dreadful decision? Timerman has given important testimony, and his courage excuses his wonderful armor-plated ego, which gets in his way when he tries to explain his own attitude before his arrest when he himself was an uneasy but fully paid-up member of the "golden ghetto," the acceptance world in which complicity or silence buys survival. (Before 1977 he had, in fact, stated openly on occasion that anti-Semitism was no more a problem in Argentina than anywhere else.) Timerman became a hero when he became a victim. Marshall Meyer, the North American rabbi to whom Timerman dedicates his book, became a hero because his heart was touched by love for the victims of the Argentine holocaust -- the thousands of people caught up in the irrational violence spawned by the hate of first the extreme left and then the extreme right.

Timerman rightly calls them "the two fascisms," but he could have described them equally accurately as "the two communisms," "the two totalitarianisms," or "the two authoritarianisms." The euphemism employed to label all too human, all to prevalent, cruelty and hate, is irrelevant. It is no wonder that today Timerman believes fiercely in the ideology of human rights and is opposed to all the ideologies of tyranny, whether "authoritarian" or "totalitarian." It took two rulings of the Argentine Supreme Court, and intensive international pressure, particularly by Patricia Derian, the U.S. assistant secretary of state for human rights, the Carter administration's Lady with a Lamp, to secure Timerman's freedom. In anger at Timerman's liberty, despite his expulsion, the loss of his nationality and most of his property, the hard-liners staged a coup shortly after he was flown out to Israel, It aborted. Almost a happy ending.