The Soviet empire was very much assimilative, so successfully that people sometimes overlook it. Its greatest leader was Georgian, while three others were Ukrainian. Parts of it ("Western Ukraine", Kaliningrad) were annexed outright after World War II, while other areas continued a Russification program that started under the tsars.
As for Poland, the Solidarity movement was quite effectively suppressed in 1981 and ceased to be an effective political force until the Polish government badly miscalculated and allowed it to reconstitute itself eight years later. The biggest mistake the Soviets made in Poland was in giving a large degree of autonomy to the Catholic Church.
As for Poland, the Solidarity movement was quite effectively suppressed in 1981 and ceased to be an effective political force until the Polish government badly miscalculated and allowed it to reconstitute itself eight years later. The biggest mistake the Soviets made in Poland was in giving a large degree of autonomy to the Catholic Church.