Fifty years ago, on May 16, Mao Zedong unleashed an attack aimed at smashing his own Communist Party apparatus from top to bottom, having concluded that it was going capitalist. “Bombard the headquarters!” he urged the masses in a famous People’s Daily article. Millions of young zealots responded, becoming Mao’s Red Guards, his fanatical foot-soldiers. Thus began China’s Great Proletarian Cultural Revolution, a period of murderous insanity that ended only with Mao’s death a decade later, in 1976.

Nothing could be further from...