If now in decline since the tumultuous events of 1989, communism was without doubt the great political movement of the twentieth century--at its peak, more than a third of the world's population lived under communist rule--and it is still a powerful force in many areas of the world, most notably in the People's Republic of China. What is communism? Where did the idea come from and what attracted people to it? Is there a future for communism? This...