Jeffrey Wasserstrom is author of China in the 21st Century (2010) and co-editor of Chinese Characters: Profiles of Fast-Changing Lives in a Fast-Changing Land (2012). He is an Asia Society Associate Fellow.

The Revolutionary, a new documentary that has begun showing on university campuses and at cultural centers, looks at the life of Sidney Rittenberg, a 90-year-old man who has had an extraordinary variety of experiences. Born into a well-to-do South Carolina family in 1921, he became a labor organizer while in college, began to study Chinese during a stint in the army, traveled to China soon after World War II — and didn’t come back to the United States for 35 years.

During his long sojourn in China, Rittenberg got to know Mao Zedong, Zhou Enlai, and other top Communist leaders and was granted the very rare distinction, for a foreigner, of being made a full-fledged member of the Chinese Communist Party. He also endured two long stints in prison, the first time (from late 1949 until 1955) as an alleged foreign spy and the second time (from 1968 until 1977) as a “counter-revolutionary,” the all-purpose charge against anyone targeted for criticism or punishment during the Cultural Revolution era (1966-1976).

Since returning to the United States in 1980, he has worked as a consultant to American businesses trying to understand what makes the giant and still nominally communist country across the Pacific tick, taught courses about China at various colleges and universities, and become a frequent media commentator on Chinese politics and culture. He also wrote an autobiography focusing on his China years, The Man Who Stayed Behind, which was published in 1993....