The most successful economy in the world is communist. The most successful political party in the world—the Communist Party of China (CPC)—has 100 million members and aims to be running the strongest state on earth by 2049. By then it may not matter whether you believe China is genuinely communist, or whether its ruling ideology is a gross distortion of the Marxist original. If its plans succeed, the CPC will get to write both the definitions and the history books. For that reason alone, we should stop treating the history of communism as a finished episode, without relevance to the choices facing us today.

Article continues after advertisement

A second reason to study the history of communism is obvious if you glance at the headlines: capitalism is in trouble and liberal democracy is imploding.…