During the Soviet Union’s Great Purge in the 1930s, a series of show trials were conducted to eliminate the potential rivals and critics of Soviet leader Joseph Stalin. Accused of conspiring to remove Stalin from power, many prominent Bolsheviks were found guilty on the basis of confessions that had either been obtained through torture or had been fabricated. They were then imprisoned or executed. At one trial, the defendants “confessed” in exchange for what promise that Stalin later broke? Discuss