Americans know the tiniest details of their presidents' private lives, from the pet names Harry Truman used for his wife to Ronald Reagan's passion for jelly beans.
Soviet citizens, on the other hand, know as little about the daily lives of their heads of state as Czar Ivan the Terrible knew about computers. Most wouldn't be able to say who Yuri Andropov's wife is - or even if he has one. Even before the 1917 Communist Bolshevik Revolution, the private family lives of the czars were cloaked in heavy layers of secrecy; part of the power and mystique of the czar's office lay precisely in his inaccessibility and mystery. This reverent fear toward ''the leader'' carried over in large part to Lenin, and his successors. It was demanded by Joseph Stalin, whose death in 1953 sent thousands of panic-stricken Muscovites running through the streets; many were injured and some killed in the mad stampede. Now Soviet dissident historian Roy A. Medvedev, who dealt with Stalinism in an earlier boo, turns to Krushchev. Medvedev, a Marxist reformer living in Moscow, treads a thin line between efforts to make the Soviet system more democratic and the threat of Party reprisals. He has written a fascinating unofficial biography of the man who came out on top after an extended period of Kremlin infighting. Nikita Sergeyevich Khrushchev, in many ways the most liberal of all the Soviet leaders since the time of the Revolution, would win out over the next three years, until he stood alone as the most powerful man in the Soviet government at the 20th Party Congress in February 1956.
Not surprisingly, one of Khrushchev's most difficult, and most important, tasks was dealing with the legacy and memory of Stalin. He began slowly to ''rehabilitate'' some of the millions of innocent Soviet citizens sentenced to long terms of hard labor in Siberian concentration camps since the late 1930s - including his own daughter-in-law. Next he arrested Beria, one of Stalin's most hated henchmen, who was responsible for countless imprisonments and executions in his job as deputy prime minister in charge of security. Shortly after, Beria was tried and executed.
But Khrushchev, courageously, opened the Pandora's box of Stalinism much wider - wider than his more frightened, and less honest, colleagues would have dared. In a speech to a closed session of the 20th Party Congress, given without text, almost extemporaneously, Khrush-chev, in an unprecedented move, denounced Stalin's crimes and the ''cult of personality'' that had made them possible. Even Khrushchev's colleagues were stunned: ''They listened in shocked silence, only occasionally interrupting the speaker with exclamations of amazement and indignation,'' Medvedev writes. No one had really known the horrifying extent of the arrests, executions, and imprisonments, of the tortures and ruined lives.
For Medvedev, who, like most ''liberal'' Soviet intellectuals and dissidents, admires Khrushchev, this ''secret speech'' was his finest hour: ''Khrushchev did what he could. His exposure of Stalin's crimes, even if not all of them, was a personal mission, a service performed by him as an individual. It remains the principal feat of his life, overshadowing all his mistakes, both before and after. He occupies a prominent place in history above all because of the report . . . and this fact is not obscured by the suppression of his name and his achievements that has persisted in the Soviet press for more than 17 years.''
The earthy, instinctive honesty that led Khrushchev to expose Stalinist history led him, too, to other democratic gestures. He encouraged newspapers to write more candidly and critically - not in the meaningless, gray, laudatory tones demanded by Stalin. He allowed writers to treat themes previously untouchable. It was Khrushchev who approved Solzhenitsyn's first novel, ''One Day in the Life of Ivan Denisovich,'' for publication in 1962. The whole Khrushchev period later came to be know as ''the thaw''; today Soviet artists remember it fondly.
It was Khrushchev's first visit to the United States in 1959 - the first by a Soviet leader - and his second a year later that have won him a special place in the hearts of Americans. The image of Khrushchev, bald head shining, removing his shoe and banging it on his desk at the UN to protest the comments of a Western delegate, will be forever imprinted in the minds of the Woodstock generation that witnessed it on televison. There was something offensive and crude - but something appealingly human and spirited - in Khrushchev's personality that Americans could understand and appreciate.
Khrushchev's frankness and impetuosity did get him into trouble, as when he called Mao ''an old galosh'' and further soured deteriorating Sino-Soviet relations. There were other failures, too, particularly in the economy. Khrushchev's grandiose promises to equal American food consumption were in shambles by the end of his years in power, the billions of rubles spent on opening up virgin lands yielding sporadic and unsatisfactory returns.
When the end came, he took it fatalistically. Accused in 1964 of a variety of ''mistakes'' - including economic mismanagement, nepotism, chaotic administrative reorganization, and poor diplomacy - Khrushchev sat silently and accepted the inevitable. ''Well, that's it,'' he said later at home. ''I'm retired now. Perhaps the most important thing I did was just this - that they were able to get rid of me simply by voting, whereas Stalin would have had them all arrested.'' Khrushchev lived peacefully in a dacha outside Moscow until his death in 1971. Today, his grave is one of those most often visited in the Novo-Dyevichy Cemetery.
Medvedev's ''unofficial'' biography of Khrushchev is a magnificent piece of work, especially considering that he wrote it while living under surveillance in Moscow, where Khrushchev is still regarded uneasily by the government and materials on his life and career are extremely difficult to obtain. (The book has not, of course, been published in the USSR.) The emphasis is more on Khrushchev's career than on his person, though we are also given evocative glimpses of his gregarious and irrepressible character. As a committed Marxist, Medvedev has profound respect and love for his subject, who attempted, if not always successfully, to democratize the Soviet system and tell the people the truth.