But it also revives unsettling questions about Polish-Soviet relations, reopening dark chapters, particularly from the Stalin years.

Polish-Soviet relations deteriorated further after 1933 with the discovery of the existence of a secret Polish intelligence organization (see Prometheism).

The whereabouts of thousands more Polish officers, however, would remain unknown for two more years, which would weigh heavily on subsequent Polish-Soviet relations.

Few issues go to the heart of Polish-Soviet relations as deeply as the Katyn massacre, in which many Poles believe Stalin wiped out the flower of Poland's leadership.

A6 A portrayal of Polish-Soviet relations by Gen. Wojciech Jaruzelski, the Polish leader, is remarkably frank.

The war ended with the Treaty of Riga in 1920, which settled the border issue and regulated Polish-Soviet relations until the German-Soviet invasion of Poland in 1939.

Polish-Soviet diplomatic relations were re-established in 1941 after the German invasion of the Soviet Union forced Joseph Stalin to look for allies.

But his address to Parliament, which was awaited by Poles with great intensity, was devoid of any startlingly new statements on Polish-Soviet relations or on international affairs in general.

Mr. Gorbachev mentioned the pain of Polish-Soviet relations in periods like World War II, but he avoided any mention of the Katyn officers.

"Momentous changes taking place in the Soviet Union have added depth and a new glamour to Polish-Soviet relations," Mr. Urban said.