< ! -- Deleted image removed : In 1937 , however , Stalin purged the Red Army of its best military leaders . Fearing that the military posed a threat to his rule , Stalin jailed or executed many Red Army officers , estimated in thousands , including three of five marshals . These actions were to severely impair the Red Army 's capabilities in the Soviet – Finnish War ( Winter War ) of 1939 – 40 and in World War II
purged
Great Purge
Military history of the Soviet Union