What did Joseph Stalin do to be cruel?

Answer 1

What do you mean? Stalin's regime executed every member of the original Bolsheviks who were the true leaders of the revolution. Not 1 member of the central committee was left alive, except Stalin him self.

He terrorized the population through the secret police and dislocated millions of families deep into Siberia. Any political opponent, IE. "enemy of the state" was relocated to the gulags and worked to death. Some scholars have suggested Stalin was mentally challenged, which was the reason he was afraid of many things, like political opponents and a free press.

Stalin used executions and disappearances to his advantage.