Fifty years ago this month, Mao Zedong launched China's Cultural Revolution — a decade of chaos, persecution and violence carried out in the name of ideology and in the interest of expanding Mao's personal power. Yet, instead of reflecting on that episode's destructive legacy, the Chinese government is limiting all discussion of it, and Chinese citizens, focused on the wealth brought by three decades of market-oriented reforms, have been content to go along. But at a time when President Xi Jinping is carrying out ruthless purges and creating his own cult of personality, burying the past is not cost-free.

In August 1966, Mao published "Bombard the Headquarters — My Big-Character Poster," a document aimed at enabling the purge of the Chinese Communist Party's leading "capitalist roader": then-President Liu Shaoqi. In the "poster," Mao called for China's youth to "pull the emperor off his horse" and start a grass-roots rebellion.

Young people responded with alacrity. "Red Guard" student paramilitary groups quickly cropped up across the country to advance Mao's will. Within 100 days, Mao had succeeded in purging swaths of the central party leadership, including Liu and Deng Xiaoping.