A heated controversy over Chancellor Helmut Kohl's decision to address a rally of Silesian exiles in June has jeopardized West Germany's efforts to improve relations with Eastern Europe and aggravated the country's tormented debate over the future of German reunification.

More than 11 million West Germans claim the eastern territories of Hitler's defeated Reich as their homeland. They or their parents were forcibly driven out of Silesia, East Prussia, Pomerania and the Sudetenland to resettle in the West when new postwar borders were established, but they have maintained a fierce loyalty to the vision that someday their lands will become German again.

Many of them are now right-wing Christian Democrats who avidly support Kohl. Besides cheering, voting and campaigning for him, they heartily embrace his conviction that a new generation of Germans born after the war should not be compelled to bear guilt or be punished for the Nazi era.

By deciding to speak to the Silesians at an emotional time when eastern and western countries will be observing the 40th anniversary of the defeat of Nazi Germany, Kohl has spurned critics and cast aside advice to keep his distance from expellees.

Some foreign policy advisers have warned of the risk that Kohl's association with the Silesians could condemn Bonn's further attempts to repair dialogue and bolster cooperation with the Soviet Union and Eastern Europe.

The political flap over the Silesians represents more than just another tale about the fanaticism of history's orphans; it illustrates the tortuous contradictions in West Germany's official attitudes toward the goal of reunification.

Foreign Minister Hans-Dietrich Genscher, who held the same post in previous Social Democrat-led governments, has tried to reassure East European countries that Bonn regards existing European borders as "inviolable."

In its 1970 treaty with Poland, the West German government accepted Poland's current western boundary, which includes Silesia, along the Oder and Neisse rivers.

Yet the Bonn government also insists that, as declared in the preamble to West Germany's constitution, it must work toward peaceful change in European borders that ultimately will bring territories now held by Poland, Czechoslovakia and the Soviet Union, as well as all of East Germany, back under one German domain.

By adhering to a paradoxical policy of respecting borders but nurturing goals of reunification "by peaceful means," West Germany has left itself vulnerable to charges that it is encouraging unreasonable hopes rather than helping an older generation adjust to new realities.

Some official maps published by the Federal Press Office in Bonn still describe East Germany as "Middle Germany" and the western half of Poland as "German territories now administered by Polish and Soviet authorities."

Recent opinion surveys have shown that many young West Germans, who were born after the war and raised on western culture with little or no exposure to Eastern Europe, reject any prospects for German reunification and share the view of allies and foes alike that a reunited Germany would be a destabilizing force in Europe.

The radical, antinuclear Greens party, and some Social Democrats, have endorsed the idea of coming to terms with Germany's division through full diplomatic recognition of East Germany as a separate country, something anathema to the Christian Democrats, who insist that there can only be one German nationality and thus one passport for all Germans.

Last year Kohl became the first chancellor in nearly two decades to speak to an expellee group. His action provoked a barrage of propaganda from Poland, Czechoslovakia and the Soviet Union claiming that he condoned "revanchist" forces eager to regain German territories lost during the war.

Shortly thereafter, East German leader Erich Honecker postponed a planned trip to West Germany, citing the "hostile climate" stirred up by the expellee organizations and right-wing Christian Democrats.

This time, Kohl found the slogan chosen for the Silesian rally in June -- "40 years of banishment: Silesia remains ours" -- too provocative to fulfill a committment to appear.

In December, a meeting of West German ambassadors based in East European capitals produced a consensus view that Kohl's attendance at the rally would inflict immense harm on Bonn's delicate relations with Eastern Europe. Foreign Ministry officials said the ambassadors claimed that the Soviet-directed "revanchism" campaign, which led to the scuttling of the Honecker visit in September and to a cooling in relations between the two Germanys, was bound to intensify in the months approaching the May 8 anniversary of the defeat of Nazi Germany.

They argued that the Soviets would seek to exploit any words or deeds by the Bonn government to resurrect the image of the German "bogeyman" in order to unite Soviet Bloc satellites behind Moscow's protection from West Germany's allegedly aggressive territorial designs.

But Kohl is renowned for his staunch loyalty to those who have proved their abiding political allegiance. "He never forgets who helped him during difficult times and election campaigns, and the expellee groups have been some of the most devoted of all," said one of Kohl's close aides.

Kohl met in Berlin last Monday with Herbert Hupka, head of the Silesian League of exiles and a member of the West German parliament. The next day Hupka announced that Kohl had endorsed an alteration in the motto and would speak to the gathering, which is expected to attract as many as 150,000 people.

The new wording reads: "40 years of banishment: Silesia remains our future in a Europe of free people."

The modification only exacerbated the political uproar. Hupka released an open letter he wrote to Kohl in which he said "Silesia is not just the home of Silesians, but the property of all Germans."

The opposition Social Democrats charged that the new slogan was even more inflammatory than the initial one. Hans-Jochen Vogel, their parliamentary leader, said Kohl was engaged in "an unseemly game" that would damage any hopes for better ties with East Germany and the rest of Eastern Europe. His deputy, Horst Ehmke, called the affair "grotesque and shameful."

East European countries reacted quickly with harsh attacks on what they viewed as proof of the Kohl government's ambitions to destroy four decades of peace in Europe in order to satisfy a yearning to reunite all lands once included in a pan-German empire.

Poland's head of state, Henryk Jablonski, told an anniversary rally in the former German city of Opole in western Poland on Wednesday that "there is not and cannot be any border issue. This question already has been finally settled. Anyone who would like to weaken us, to reverse the course of history, anyone who does not want to accept history's just verdict, is not only an enemy of Poland but an enemy of peace in Europe and the world."

In Czechoslovakia, the state radio said Kohl's agreement to attend the Silesian meeting "at a time when mankind prepares to celebrate the 40th anniversary of of the defeat of fascism arouses indignation."

"In spite of the fact that the revival of revanchism can only poison international relations, Chancellor Kohl promised to attend this year's revanchist rally in Hannover that will raise territorial claims against Poland," the radio said.

East Germany's communist authorities, who remained circumspect in earlier waves of Soviet Bloc criticism against West Germany, joined in the current attack with an editorial in the party daily Neues Deutschland that said the Silesian rally motto "slandered the victims of Nazism."

"With an all-too-transparent trick, they want to achieve everything that Hitler failed to achieve, within a Europe dominated by Bonn and stretching to the borders of the Soviet Union."

"This is no longer politics, this is pure madness," the editorial said.

The furor grew louder Friday, when a magazine representing Silesian refugees ran an article suggesting that the West German Army could sweep into Eastern Europe and reunify Germany. It imagined that the Army would meet only token resistance because the "overwhelming part of the population" would hail the West Germans as liberators.

The West German government quickly denounced the article as "irresponsible, damaging and foolish." The author of the piece, Thomas Finke, was summarily booted out of Kohl's ruling Christian Democratic Union.