The Red Army, however, had been hindered by Soviet leader Joseph Stalin's Great Purge of 1937, reducing the army's morale and efficiency shortly before the outbreak of the fighting.
然而红军在1937年苏联领导人约瑟夫·斯大林的大清洗中受到削弱，战争爆发之前军队的士气及战斗能力有所降低。