The Bund members took part in the Committee for the Salvation of the Motherland and Revolution. On November 7–9, 1917, the Central Committee of the party condemned the October coup and demanded the formation of a government from all socialist parties. In the elections to the Constituent Assembly, the Bundists ranked 2nd among the Jewish parties, losing to the bloc of religious parties and Zionists.

 

In 1917–1919, the Bund ruled out the possibility of a violent struggle against Soviet power, gradually abandoned the slogan of restoring full democracy, and recognized the need for the dictatorship of the Soviets to protect the “socialist gains”. At the same time, it identified itself as a non-communist and oppositional organization that did not share many of the methods of the Bolsheviks, who competed with the Bund by organizing Jewish communist sections under the committees of the Russian Communist Party (Bolsheviks) – RCP(b). The shift of the Bundists towards the Bolsheviks was first of all caused by the unprecedented scale and brutality of the Jewish pogroms in the territories controlled by the anti-Bolshevik forces. Back in May 1918, the Bund noted that the Civil War created a particularly favorable environment for the growth of anti-Semitism. In the Bolsheviks and the Soviet government, the Bundists saw a force capable not only of protecting Jews from violence and liquidation but also of freeing them from national humiliation and ensuring social equality.

 

The left-wing Bundists began to create communist organizations in Belarus and Ukraine: in February–March 1919, the Communist Bund (KomBund) and in May 1919, the Komfarband (Communist Union), which merged with the Communist Party of Ukraine (August 1919). In March 1919, at the 11th Conference, the Bund decided to support the Soviet government but remained in opposition to the RCP(b). After the conference, it was announced that the members of the Bund would be mobilized to join the Workers’ and Peasants’ Red Army.

 

At the 12th Conference (March–April 1920, Moscow), the Bund split: the victorious left-wing decided to quit the Menshevik Party and join the RCP(b) and the Communist International (Comintern). The Bundists tried to preserve their autonomy within the Bolshevik Party, but the committees of the Politburo of the Central Committee of the RCP(b) and the Comintern rejected the project of organizational autonomy proposed by the Bund. After that, in June 1921, the Central Committee of the Bund announced the liquidation of the party.

 

In 1920, the right-wing Bundists united at their conference in Vitebsk (April 1920) to form the Social Democratic Bund and share the common fate of the Mensheviks: some of the personalities ended in exile, the others were repressed. In the 1920s and 1930s, the Bund operated in Poland as a legal political party. During the Second World War, it took part in the Resistance movement.