Possession of the territories that constitute Lithuania, western Belarus, and the western Ukraine, where most Poles of the former Soviet Union live, has been contested for centuries between the Polish and Russian states. This region, along with a substantial portion of eastern Poland, came under Russian rule in the various partitions of the Polish Commonwealth in the eighteenth century. When the Polish republic was restored following World War I, much of this territory was returned to Poland. At the conclusion of World War II, a large portion of eastern Poland was again transferred to the Soviet Union.
The history of Poles in the former USSR included periods of cultural autonomy and repression. In the 1920s, under Lenin's policy of cultural toleration, two Polish autonomous regions were established, one in Byelorussia and one in the Ukraine. Polish was the official administrative language in these areas and education and publishing in the Polish language proliferated throughout the western republics. There was considerable official toleration of the Catholic church.
In the 1930s the mostly rural Polish population was highly resistant to the collectivization of farms, and this brought them into direct conflict with the Soviet leadership. The autonomous regions were liquidated, hundreds of thousands of Poles were deported to Siberia and Kazakhstan, and cultural expression was severely limited. The use of the Polish language in schools and in the press was restricted, and churches were closed. During World War II the eastern half of Poland also came under Soviet occupation, in accordance with the Molotov-Ribbentrop Pact. Many Poles in the occupied lands, particularly intellectuals and business leaders, were deported to Siberia. Thousands of Polish army officers were massacred in the Katyn forest by their Soviet captors/allies.
After World War II the Soviet Union gained additional territory from Poland. Some of the Poles in the USSR, particularly those in the newly acquired areas and those who had been exiled to Siberia, were repatriated to Poland, but the overall population of Poles in the Soviet Union did not decrease.
From the end of the war, the Soviet authorities generally suppressed Polish cultural expression, although forcible population transfers ceased. Visiting across the Polish-Soviet border was strictly limited until the latter 1980s. There is evidence that Poles are becoming assimilated into local populations; the percentage of the population speaking Polish as a first language is declining.
As a result of the long history of conflict between Russians and Poles, ethnic relations between the two peoples are rather tense. Poles associate Russians with the atheist Soviet state. Although there is some intermarriage between these two groups, the practice is strongly discouraged.
In the western republics, the relationship between Poles and the majority ethnic groups is more complex. There are strong economic and cultural pressures for assimilation. In these regions, however, which were formally parts of the Polish state, the Soviet central government at times encouraged Polish cultural expression and efforts to gain local autonomy in order to counter the nationalist aspirations of these republics. This had been particularly true in Lithuania and the Ukraine. Currently, in Lithuania, the Polish minority has proposed the addition of Polish language, history, and culture to the school curriculum as a means of making the Poles an equal partner in the new Lithuanian state.