Along Europe's great fault line, where World War II began and left the German and Polish capitals both in ruins, Sunday is a day steeped with symbolism: A German chancellor will be in Warsaw for the first time to pay homage to the dead in the doomed Warsaw Uprising of 1944.

Sixty years after the rebellion, in which the Nazis killed 200,000 people, Germany's place in the emotional equation is still a complicated matter. And so is Russia's. Looking both west and east, Poles have much to resent -- the Germans for perpetrating the slaughter, and the Soviet army for not intervening, even though it was parked at the gates of Warsaw.

On top of that, the revolt was written out of Polish history during its 40 years of communist rule and, as a result, was eclipsed in the world's consciousness by the well-known and internationally documented Warsaw Ghetto Uprising of a year earlier.

The 63-day uprising began on Aug. 1, 1944, when Allied victory over the Third Reich seemed imminent, with D-Day forces sweeping toward Germany from the west and the Red Army sitting outside Warsaw, ready for the final march on Berlin.

It led to SS leader Heinrich Himmler's infamous order to his troops: "Every inhabitant should be killed, no prisoners are to be taken, Warsaw is to be razed to the ground and in this way the whole of Europe shall have a terrifying example."

Today, Poland's relations with its German neighbor are in some ways closer than ever, and Chancellor Gerhard Schroeder's office says he is honored to be invited to a commemoration of "enormous historical and symbolic importance."

But official gestures aside, new tensions are brewing -- brought on, ironically, by the closer relationship since Poland joined the European Union on May 1.

The discord is rooted in World War II, which ended with the Allied powers giving Poland a swath of prewar Germany, a decision that uprooted millions of ethnic Germans from their homes.

Some Germans have threatened to use E.U. courts to regain their property, and Poles deeply resent their portraying themselves as victims of a war that Adolf Hitler started by invading Poland in September 1939.

How easily emotions are inflamed became clear recently when the main German expellee lobbying group commemorated the Warsaw Uprising in a Berlin church, without inviting any Polish delegates.

The head of the Federation of Expellees, Erika Steinbach, said at the event that her aim was reconciliation and dialogue. "We want to sympathize, and we yearn for the sympathy of others," she said.

But Polish politicians were outraged, among them 82-year-old Wladyslaw Bartoszewski, a former foreign minister and Holocaust survivor who fought in the uprising.

"The Warsaw Uprising is something sacred for many Poles, especially for the residents of Warsaw," he told the Gazeta Wyborcza newspaper. "Hands off this sacred thing!"

Kazimierz Ujazdowski of the opposition Law and Justice party called Steinbach "impudent and aggressive" and demanded that the German government disavow the group's actions.

In fact, Schroeder and his government, as well as German President Horst Koehler of the center-right opposition, have distanced themselves from Steinbach's group and have urged Germans to abandon all demands for compensation.

Even before the latest blowup, Warsaw Mayor Lech Kaczynski ordered experts to estimate the damage done to Warsaw during the uprising, threatening to sue Germany for the cost of reconstruction.

Though the German government has given some compensation to forced and slave laborers of the Nazi era, it has never paid for rebuilding Warsaw. Studies done in the late 1940s estimated the total damage at about $30 billion.

Today, cross-border businesses, German investment in Poland and university exchanges bring Poles and Germans together with growing frequency, but mistrust and ugly stereotypes on both sides persist. Many Germans consider Poles lazy and inclined to criminal behavior, while Poles view Germans as arrogant.

Germany isn't the only issue in contention. The Russian ambassador angered Polish veterans and historians by remembering the uprising as a "united fight against a common enemy."

"The fruits of our common victory are sacred," Nikolai Afanasievski wrote in a commemorative booklet prepared by the organizers of Sunday's ceremony.

In fact, Poles see the Soviet Union's behavior during the uprising as a monstrous betrayal.

Moscow initially called on the Poles to rise up, but when the Polish Home Army -- which was both anti-Nazi and anti-Soviet -- began fighting, the Soviets stood back and let the slaughter happen. It was a bitter prelude to the 40 years of communist rule and Soviet hegemony that would follow -- a time during which there were no monuments to the uprising and it was officially ignored, with textbooks mentioning it only in passing.

"Can you imagine if Washington, D.C., had been completely destroyed and no monument was allowed to its destruction for 45 years?" Norman Davies, an Oxford University historian who published a book last year on the uprising, said in a recent interview.

So thoroughly was the silence imposed that for a long time, outsiders knew only of the Warsaw Ghetto Uprising by the Jewish remnant in the capital. Even the German president of the time managed to confuse the two revolts when he responded to an invitation to attend the 50th anniversary commemoration in 1994.

The Poles, while inviting Germany's chancellor to Sunday's ceremony, have pointedly limited Russian participation to the ambassador, and he hasn't yet said whether he accepts the invitation.

Poland's reorientation westward -- and the part it plays in the U.S.-led Iraq coalition -- is highlighted by the decision to invite U.S. Secretary of State Colin L. Powell.

Today, the historical blanks have been amply filled in. As part of this year's remembrance, a new museum to the uprising will be opened, and Warsaw today is dotted with plaques commemorating Poles who fell during the uprising. Janusz Mieczkowski was 18 when he fought in the uprising, driven by a patriotic duty still vivid today as he prepares to take his place among about 3,000 survivors of the uprising who will attend on Sunday.

"We lost our independence, and the Germans were very cruel to us," Mieczkowski said.

By now he can forgive, he said. "The Germans today are not the ones of that time."

Uprising veteran Zbigniew Scibor-Rylski looks over names of the fallen at a new museum devoted to the 1944 fight against the Nazis.Uprising veterans and their relatives collect their invitations to Sunday's commemoration, which the German chancellor is to attend. In the background is the event's official poster. A vintage photo of a street in Warsaw destroyed in the 63-day uprising, which claimed the lives of 200,000 Poles.Wieslaw Paszta displays a replica of a clandestine radio transmitter whose broadcasts kept up Polish fighters' spirits during the Warsaw Uprising.