Washington — One of America's foremost Sovietologists predicts that the Soviet Union will launch an enormous ''peace offensive,'' directed primarily at Western Europe, by early next year.
Based on his research into Soviet materials as well as a recent trip to the Soviet Union, Seweryn Bialer of Columbia University also expects that once Soviet President Leonid Brezhnev passes from the scene, the Soviets will go much further in their diplomatic initiatives.
In the post-Brezhnev era, Dr. Bialer predicts that the Soviets will broaden their diplomatic offensive to include half a dozen peace initiatives that would involve, among other nations, Angola, Afghanistan, China, Japan, the United States, and most important, a continuing effort to court Western Europe.
Bialer, who is Ruggles professor of political science at Columbia and heads its Research Institute on International Change, says he thinks that despite its tough tone, President Brezhnev's speech Oct. 27 to military officers does not necessarily mean, as some analysts have concluded, an escalation of the nuclear arms race. In Bialer's view, the Brezhnev speech shows that a serious dispute between Soviet military men and civilians is continuing, with Brezhnev playing a mediating role.
Whatever the outcome of that dispute, Bialer sees more carrot than stick in the Soviet approach to the world for the next year or two. This, he says, is because the Soviets are not eager to test President Reagan's tough approach to them; have their hands full with Poland and other trouble spots; want to continue detente with Western Europe; and are deeply engaged in establishing a new leadership to take charge when President Brezhnev passes on.
Bialer expects the Soviets to take heart from the American midterm election results, which he says they will no doubt see as a moderating influence on President Reagan's foreign policy and military spending plans.
In an interview with the Monitor, Bialer predicted that in the post-Brezhnev era, the Soviets will:
* Offer to restore detente with the US and display greater readiness for the kind of compromise with the Americans that such a restoration would require;
* Make dramatic new overtures to normalize relations with China, perhaps even including an offer to withdraw some Soviet troops from the Chinese border.
* Court Japan by returning to a 1957 agreement that would allow the return of the southernmost Kurile islands to Japan in return for a new Japanese agreement to help develop Siberia.
* Intensify efforts to reach an international settlement over Afghanistan that would permit a withdrawal of Soviet troops but leave in power a regime that isn't hostile to the Soviet Union.
* Bargain over an at least partial withdrawal of Cuban troops from Angola.
But the Soviets' highest priority in the coming year, according to Bialer, will be to prevent implementation of the NATO decision to deploy new American nuclear missiles in Western Europe starting in December 1983.
The Soviets will attempt to show the West Europeans that the Americans are the ones who are holding up new arms-control agreements by refusing to negotiate in good faith, Bialer said. This has already begun to a degree. On Nov. 2, Soviet Col. Gen. Nikolai Chervov, head of the Soviet general staff department on strategic weapons, accused the Reagan administration of deliberately seeking to create an impression that progress was being made in two sets of US-Soviet nuclear arms-control negotiations in Geneva while making proposals that it knew in advance to be unacceptable to the Soviets.
Bialer expects the Soviets to launch new arms control initiatives, particularly in the realm of US-Soviet talks on medium-range nuclear weapons based in Europe. The Soviets, he says, will try through such initiatives and through other proposals to influence the West German elections next March.
President Reagan's decision to impose sanctions against European companies providing equipment for the Soviet natural gas pipeline in Western Europe has divided the Western alliance and thus played into the Soviets' hands, according to Bialer. The professor described the pipeline decision as ''Reagan's ideological indulgence.''
In the Middle East, the Soviets will intensify their efforts to gain influence in Iran, according to Bialer. But they will move with caution, he said , because they have more on their hands than they can cope with at the moment in Poland and Afghanistan and in their costly commitments to Cuba, Vietnam, Ethiopia, and Angola.
Bialer said that from a military point of view, the Soviets were capable of staying in Afghanistan indefinitely. In his view, Soviet operations there do not involve high casualties. But the Soviets are interested in a settlement of the Afghanistan question, said Bialer, because it has become a ''tremendous political embarrassment to them.''
Given the Soviet Union's ''overextension'' and the firm posture toward Moscow taken by the Reagan administration, Bialer says that the US and the Soviets have now entered a period of ''higher tension without a major danger of confrontation.''
Bialer says that the Reagan administration has been fortunate so far in confronting a relatively passive Soviet Union, which has been ''retrenching.''
''But this luck may not hold,'' he said.
The Sovietologist criticizes the administration for engaging in what he calls a ''one-sided'' approach to Moscow.
''They only use the stick with the Soviets - and moreover a rhetorical stick - without providing the Soviets with any alternatives other than suicide or capitulation,'' Bialer said.
''The administration should indicate to the Soviets not only its determination to confront them but also its willingness to change policy in the direction of positive incentives should the Soviet Union moderate its international behavior.''