Aron Isaakovich Vainshtein, (23 November 1877 – 12 March 1938) known by the nom de guerre Rakhmiel, was a Jewish socialist activist and politician in Soviet Belorussia.

[3] During the early period of the Bund movement, Vainshtein's Warsaw faction opposed the line of calling for Jewish national rights of John Mill's Geneva-based leadership.

[1] As the Bund split at the April 1920 twelfth congress, Vainshtein and his sister-in-law Esther Frumkin led the pro-communist Kombund majority faction.

[1] While heading this body, he was accused by the Yevsektsia (Jewish Section of the Communist Party) of implementing a petty bourgeois Bundist economic policy.

[7] At an Extraordinary All-Russian Bundist Conference, held in Minsk on March 5, 1921 the delegates representing some 3,000 party members debated disbanding the Communist Bund.