Under Russian and Soviet rule
In the 1920s, the Soviet government encouraged the development of Belarusian culture in the part of the country under its control, while the Polish government tried to suppress all expression of Belarusian identity in the part under its rule. This helps explain the strength of pro-Russian and pro-Soviet attitudes in Belarus.
War devastated Belarus
In 1939, the Molotov-Ribbentrop Pact led to Nazi Germany’s occupation of Poland (except for western Belarus) and the Soviet annexation of western Belarus, which was incorporated into the Belarusian SSR.
In 1941, the Nazis overran Belarus as they invaded the Soviet Union. The war devastated Belarus, leaving its cities in ruins and its population reduced by one quarter.
After the war, the cities of Belarus were rebuilt and its economy restored. By the 1970s, a new industrial base was taking shape, including textiles, motor vehicles, chemicals, and electrical equipment. Belarus’ industry was completely integrated into the Soviet economy and dependent on Russia and other Union Republics for fuel and other supplies. Belarus underwent steady Russification, so that by 1980 over a quarter of Belarusians no longer used Belarusian as their primary language.