Song Binbin, who has died, probably aged 77, became a poster girl for the bloody Chinese “Cultural Revolution” when on August 18 1966 she was photographed overlooking an immense rally in Tiananmen Square, pinning a red armband, symbol of the Red Guards, on the arm of the Chinese dictator Mao Zedong. Two weeks earlier she had taken part in the murder of Bian Zhongyun, deputy principal of the Beijing high school she attended, one of the first – and one of the most notorious – of the murders that inaugurated a decade of slaughter in which between one and...