World attention is now focused on changes in the Soviet leadership. But greater long-term possibilities for the United States and the Western world to ease the confrontation between East and West may lie deeper - within changes in Soviet society itself.
From afar it seems that the ice that covers the surface of Soviet society is still unbroken. But deep beneath, eddies and currents have begun to stir. Change comes slowly in the Soviet Union. There will be no sudden explosion of democracy or liberalism, as some in the West hope for.
But change is on the way. It could loosen up Communist Party rule in the coming decades. It could force the party to spend more on light industry, less on heavy. No one can predict what will happen. But it is in the interests of the US, and the West, to encourage this change as best it can.
Instead of the classless society Vladimir Ilyich Lenin thought he was creating 65 years ago, the Soviet Union is now an extremely class-conscious one. Instead of just the two classes permitted by Marxist ideology - worker and peasant - the Soviet Union has at least five.
Perhaps the most interesting is an emerging, strengthening urban middle class , which itself has three separate layers, upper, medium and lower. About 23 million people and their families fit into it, or some 46 million people in all, one Soviet citizen in about six.
This middle class is less and less willing to accept the shortages, the economic slowdowns, the lack of spacious housing, the rough and ready medical care, the long search for fresh meat, that characterize so much of the USSR today.
It wants as much privilege and status as it can obtain. It knows that the superclass of party, government, scientific, KGB, military, and other elites above it have these privileges.
For most of the last 10 years, the Soviet middle class has been exposed as never before to the winds of detente with the US and Western Europe. It has listened to Western radio broadcasts (before many were jammed after the Solidarity uprising in Poland in mid 1980).
In Moscow, Leningrad, Kiev, Minsk, and Tallinn, the 1980 Summer Olympics staged events, bringing tourists and new clothes and consumer goods to see.
The 18 years of Mr. Brezhnev's leadership has seen a further massive growth of the cities in the Soviet Union. Twenty now contain more than 1 million people each, and 45 more than half a million - a staggering change from traditional Russia.
As late as 1940, two-thirds of all Soviet people lived in rural areas. In the last 40 years the situation has reversed. So many have fled the boredom and isolation of the farm areas for the lights of the cities that, by early 1979, when the most recent Soviet census was taken, two-thirds of all people lived in cities.
This is an entirely new situation for the Kremlin.
The Kremlin hopes that the thirst for comfort, style, color, privilege - the hunt for better jobs, housing, food, a car, good university places for children, private medical care, better clothes, more travel - will turn out to be a control lever for the party. Its aim is to enhance its own control by regulating the flow of this privilege to those it favors, and denying it to those it does not.
But it is indeed possible that privilege is a two-edged sword. In the long term, the search for privilege is a subversive one. It undermines collectivist Marxist-Leninist ideology. The party will have to perform better on the economy than it is now doing.
This new middle class has no political power. It does not directly affect what the Kremlin does abroad. But as the years go by, new Soviet leaders will have to listen to it. Unlike the impression held by many Westerners, the party listens hard to what its people are saying. One of the reasons Yuri Andropov had the reputation of being a liberal within the KGB when he was its chairman is that he was the chief listener, the chief surveillance officer.
As Anthony Polonsky, specialist on Eastern Europe at the London School of Economics, puts it, ''Secret police heard so many new ideas as they listened in that they actually tended to be liberals under the tsars, and the same is true now.''
Polonsky also agrees that widespread privilege can be dangerous for the party. ''When Edward Gierek [former Polish party leader] began bringing in goods from the West in great quantities in the 1970s, it ultimately worked against him ,'' he said. ''Poles saw what they'd been missing, and demanded more. Privilege was not a control lever but a destabilizing influence. The same could well work out to be true in the USSR.''
The change in the Soviet Union is more gradual, and less immediately alarming to the authorities.
The five classes I observed during four and a half years as Moscow correspondent for this newspaper were: the superclass of the topmost elites - the Politburo, the Secretariat or executive committee of the Central Committee, top armed forces marshals and admirals, the presidium of the academy of sciences , leading KGB officials, and more - the military officer caste, the middle class , the urban class, and the rural class.
The bulk of the people still belong to the last two. Under Stalin they endured famine in 1932 and 1947, purge, war, privation, hardship. Under Nikita Khrushchev new housing was built, food improved, contacts with the West widened a little, and prospects began to brighten until the early 1960s, when the post-Stalin thaw began to freeze over.
When Mr. Brezhnev took over in 1964, he was determined not to repeat the Khrushchev experiments with agriculture, industry, and the party apparatus. His method was gradual change, more investment in agriculture, a stronger military.
Life for most people has improved - but slowly. The USSR is still the poorest major country in Europe - as it has been for the past 1,000 years.
But changes have crowded in. The urban bourgeoisie has mushroomed in size, and its expectations steadily rise. The age of automation and electronics comes late to Soviet society, but so many white-collar workers are now needed to run the military-industrial complex that even the official statistical bulletins agree that a subclass of ''intelligentsia'' now exists within the official working class.
These are the kind of people who form the new middle class - the skilled white- and blue-collar workers, the technicians and engineers. They join the middle and lower levels of party officials at city district level and below; the top staff at institutes affiliated with the USSR Academy of Sciences; the supervisors and other senior people in government ministries; performing artists , writers, architects, surgeons, lawyers, doctors, and many more.
Their aim is not to seize political power. They couldn't if they tried: The party has 4 million men under arms, a network of secret and overt police, and informers everywhere.
No, the middle class wants a better life first. After that, it will worry about other things. It wants Western goods, Western styles. It does not necessarily want Western democracy because it has only known communist centralism.
The ice of conformity and central rule still lies thick across Soviet society. Mr. Brezhnev's passing is an opportunity for the West, not to try any sudden new moves that could upset the new collective leadership, but to reflect on how to encourage the middle class in its growth and demands on its own party.