SOVIET BLOC IN TRANSITION : Ligachev Sees Peril in a United Germany : Europe: Conservative leader urges Soviets to oppose reunification. His firm stand makes this a Kremlin issue.

The Soviet Union’s leading conservative politician forcefully warned his nation Tuesday to use all its influence to oppose German reunification as a threat to Soviet security.

Yegor K. Ligachev, a senior member of the Communist Party’s ruling Politburo, told a meeting of the party’s Central Committee that the reunification of East and West Germany would create a threatening new economic and military power in the center of Europe and upset the postwar stability of the Continent.

“We must not overlook the approaching danger from Europe--namely the accelerated process of reunification of Germany and in practical terms the absorption of the Germany Democratic Republic,” Ligachev told the Central Committee, according to the official Soviet news agency Tass.

“I think it is time to recognize this new danger and to speak out in full voice, the party and the people together.”

Ligachev’s firm stand in the course of the tumultuous debate over President Mikhail S. Gorbachev’s proposed political reforms makes German reunification, quite unexpectedly, a major domestic issue here and is likely to inhibit Gorbachev’s freedom of action on the question.

Soviet opposition to German reunification would not only make the process far more difficult, Western diplomats said, reacting to Ligachev’s speech, but could quickly become a point of contention that would slow the improvement of East-West relations.

“Although we have started from entirely different positions, we have been coming together quickly and easily on ways to approach this question, though a solution is some distance away,” a West European ambassador said Tuesday evening after reading Ligachev’s speech to the closed-door party conference.

“Suddenly, we have not just a serious complication but a potential barrier in the process. . . . Real Soviet opposition, active Soviet opposition might be futile, but it would create very serious strains in European and East-West relations and could quickly become destabilizing,” the diplomat said.

After declaring only two months ago that German reunification was “not on the agenda,” Gorbachev had come to accept it as inevitable and had declared Moscow’s support of Berlin’s plan for a stage-by-stage drawing together of the two German states--although with warnings that the process must be carefully managed to ensure European stability.

Eduard A. Shevardnadze, the Soviet foreign minister, had declared Friday, “We favor the eventual creation of a united, peaceful, democratic Germany,” but he again asked for safeguards.

Shevardnadze proposed that the issue be discussed within the context of the continuing negotiations on European security and cooperation and that perhaps a referendum would eventually be held among the nations of Europe on the question.

Soviet foreign policy specialists had also begun discussing other ways as well to handle the issue.

One idea under high-level consideration was a Soviet-American discussion leading to a resumption of talks among the four victorious Allied Powers of World War II--Britain, France, the Soviet Union and the United States--on a German peace treaty. These talks would define the terms for reunification, with confirmation to follow, first by members of the North Atlantic Treaty Organization and the Warsaw Pact, then finally by all 35 participants in the European security talks.

But Ligachev, warning of the danger from a reunified Germany and lamenting the consequent collapse of East Germany as a Communist state, called for the Soviet Parliament to debate the issue.

With feelings about Germany still deep because of Nazi Germany’s invasion of the Soviet Union in World War II and the subsequent deaths of more than 20 million Soviet citizens, this could present Gorbachev with a major foreign policy controversy--at a time when he is already battling to transform the Soviet political and economic system.

Pleading for concerted international efforts “not to allow another Munich,” Ligachev implicitly compared the possible reunification of the two Germanys with Nazi Germany’s absorption--with Western approval--of the Sudetenland in Czechoslovakia in 1938, setting the stage for the start of World War II in Europe a year later.

“It would be unforgivable short-sightedness if we did not see that a Germany with great economic and military potential is looming on the horizon again,” he said. “Real efforts of the world community and all democratic forces are needed to prevent any raising of the issue of revision of postwar borders.”