"Communism, which came to control a third of the planet in a generation, was the most important political movement of the past century. It carried out what other socialists had only talked about, abolishing capitalism and creating publicly owned, planned economies. Its crimes and failures are now so well rehearsed that they are in danger of obliterating any understanding of its achievements - both of which have lessons for the future of progressive politics and the search for a social alternative to globalised capitalism."