 Poland was shifted westwards, thus giving up most of the disputed territories in the Second Polish Republic, those territories were mostly incorporated into the Lithuanian SSR, itself one of the Republics of the Soviet Union.At the same time, many Poles from the Kresy area were forcibly repatriated west to the "Recovered Territories", and the Polish minority in Lithuania (or Lithuanian SSR) was also significantly downsized.Under the eye of the Soviet Union, the various ethnic groups in the Eastern Bloc were to cooperate peacefully in the spirit of Proletarian internationalism, and that policy, coupled with the population migrations limiting the size of both minorities in the respective regions, resulted in a lessening of tensions between Poles and Lithuanians.