Sentence:  In each of the last , the trial marked the beginning of a new course : in Moscow the liquidation of the Old Bolsheviks and the tightening of <WSD>Stalin</WSD> 's dictatorship ; in the United States the initiation of militant anti Communism , with the repentant ex Communist in the vanguard . 
Meaning of the word marked with <WSD> tags:  Russian leader who succeeded Lenin as head of the Communist Party and created a totalitarian state by purging all opposition (1879-1953)