The Life and Death of Communism : THE COMMUNISTS: The Story of Power and Lost Illusions, 1948-1991 <i> By Adam Ulam</i> , <i> (Charles Scribner’s Sons: $27.50; 528 pp.) </i>

“The Party is the brain, honor and conscience of our epoch,” was one of the more imaginative placards emblazoned across the Soviet Union in the mid-1980s, thanks to the tireless efforts of throngs of Communist Party functionaries responsible for “propaganda and agitation.” On the other side of the Cold War chasm, President Reagan was offering a different, if not much more complex, definition: The Party is “the focus of evil in the modern world.”

Seven years ago, to the accompaniment of similar rhetoric, a young, attractive, dynamic new General Secretary took command of the Party. The focus of evil had produced a leadership that would free the world of the fear of nuclear war and erase its crippling and demoralizing division into two social systems. In 1917, nobody expected the Communists to gain power and keep it for 74 years. In 1991, nobody expected them to lose it so quickly and decisively.

So what was communism all about? Adam Ulam, director of the Russian Research Center at Harvard University, author of a number of important books on the history of the Soviet Union and a demobilized Cold Warrior, has come up with some useful answers, which are surprisingly free of animus toward the subject.

Ulam traces the evolution of Communist states and parties since the late 1940s, when the influence of the world Communist movement was at its peak. “Inherent in that menace was the suspicion in the West that communism was strong not only because the USSR was now one of the two superpowers. Capitalism and its political philosophy, liberalism, had their reputation severely damaged by recent events ranging from the Great Depression to the collapse of France in 1940. Communism, as shown by the Soviets’ wartime performance, had proved its vitality. Even in democracy’s traditional preserve there were many in 1948 who saw in Marxism-Leninism the wave of the future.”

Western fears soon reached extraordinary proportions. The idea that the world was confronted with a relentless Commmunist drive for domination, organized as a global conspiracy with headquarters in Moscow, formed the rationale for the Western counteraction. Cold War battle lines were drawn to usher in several decades of costly and risky struggles for world control.

In reality, “the USSR was never powerful enough nor ready for a confrontation with the West, as it was then believed . . . The USSR’s ominous and defiant posture was in fact designed very largely to mask its vulnerabilities.”

At the very heart of the Communist system was a profoundly dubious heritage. The Soviet Union was born out of a major Russian revolution, the leaders of which were convinced that their coming to power in Russia was just the first act of a global demise of capitalism. Indeed, most of them thought that unless the Russian example were followed by at least some Western countries, they were bound to fail. And they were right. The Russian example was not followed, while the attempt to build a “Communist” society in Russia alone resulted in a civil war and economic collapse.

Yes, Russian Communists did win the civil war at tremendous costs, but history had played a cruel trick on them. Capitalism was not about to die; communism would not work. So Russian Communists proceeded to build a bureaucratic, highly centralized one-party state that would undertake to restore and modernize the country’s economy and pursue “peaceful coexistence” with the West.

And yet, becoming increasingly focused on what it called “peaceful construction,” that state could not afford to sever its ties to the 1917 revolution--not only because the ideas of class war and “proletarian internationalism” were crucial to legitimizing the Communist Party’s monopoly control of society but also because revolutionaries in a lot of other countries saw the Soviet Union as a natural ally, if not a successful model.

The seven-odd decades of Soviet communism in power were like a wild roller-coaster ride through history, with the riders uncertain about the direction, fearful of a crash, swept by forces they could barely understand or control, unable to jump out--and desperately trying to maintain a respectable composure in the process.

Here is Stalin, seemingly winning the fight not only for his brand of communism but for his country’s life during devastating World War II. But it very soon becomes clear that his victory is Pyrrhic. His regime can maintain stability only by sending new millions to the Gulag and by imposing an even harsher form of mind-control than before the war.

The new Communist regimes born out of the postwar crises immediately try to assert their independence of Moscow, while those installed by Moscow itself cannot seem to get their act together. Tito’s Yugoslavia breaks with Stalin openly, while Mao’s China, for its own purposes, chooses not to reveal its increasing conflict with the Kremlin. While new revolutions create new problems for Stalin, his revolutionary rhetoric helps the West mobilize for a Cold War and an arms race the Soviet Union can hardly afford.

No wonder, then, that within days after Stalin died in 1953, his successors began frantically searching for new policies. Most of Ulam’s book profiles Communists who are trying to run away from Stalinism and never quite succeeding--until, of course, Gorbachev comes along. Ulam has at least one kind word to say about almost each of them, even Brezhnev.

Still, he recognizes that all were primarily concerned with keeping their party, and thus themselves, in power. And all knew that to achieve this goal they had to both manipulate and negotiate with other countries: giving in here and lashing back there, playing “the world revolutionary process” today and “peaceful coexistence” tomorrow.

In the Soviet Union, as in its satellites, however, new generations were growing up and yearning for peace, freedom and a better life. Increasingly, state and society were going their separate ways. Gorbachev’s greatness lay in recognizing the need to reunite them by letting society have the upper hand. His biggest and most felicitous mistake was that he thought that by doing so he was also saving communism. If he had been less of a true believer, he would have never implemented glasnost.

Thriving on adversity and martyrdom, communism was a strange movement indeed. It needed enemies, and it had them aplenty.

Meanwhile, its real gravediggers have turned out to be its own leaders. Stalin killed and jailed more Communists than Hitler, in order to subjugate the movement to his authority. Then Khrushchev shattered the movement further by exposing Stalin’s crimes. Brezhnev’s corrupt and cynical bureaucratic reign wiped out almost all of the remaining true believers.

A byproduct of the failure of Western civilization to cope with its economic and social problems, communism must be seen as a creation of both East and West blocs. Its claim to be an effective alternative to capitalism failed, though the very fact that an impressive political power presented such a claim compelled capitalist leaders to introduce serious changes in their system, which helped stabilize it.

Having helped capitalism survive and reform, communism was left without a mission. It had to bow out. And it did so, leaving behind a lot of newly free people and a lot of pressing social problems. But, as we go about solving them, we won’t have the Communists to kick around any more.