The ghost of Tiananmen stubbornly refuses to leave the mansion of Chinese politics. Since Deng Xiaoping mobilized the PLA against the demonstrators in Tiananmen Square in 1989, the Chinese government has refused to review the event or its suppression. A brief flurry of publications and public gestures affirmed the correctness of the decision in the months after 4 June until all official acknowledgments of the incident were withdrawn from circulation in November 1989: Tiananmen was best forgotten. The 15th-year anniversary in June 2004 might have been an appropriate moment to lay the ghost to rest. Jiang Yanyong, the PLA doctor who publicized China's failure to deal with SARS in 2003, attempted to puncture the silence by calling for an official re-evaluation, but he achieved little beyond being made to disappear for seven weeks. The power of silence is strong, but so too is the power of memory. Tiananmen will remain an unexploded mine on the battlefield of Chinese politics until it is properly defused.

Dingxin Zhao's study of the sociology of knowledge and action during the democracy movement provides a rich and persuasive portrait of how this power came into being. The core of his argument is that the democracy movement arose at a particular moment of alienation – a naively idealistic but disillusioned intelligentsia facing a post-ideological regime of dwindling legitimacy – within a particular ecology of social interaction – a poorly organized society facing a state that could penetrate from above but not inspire investment from social actors below. By astutely blending structural and contingent factors, Zhao is able to show how student activists and state representatives produced effects or forced reactions that neither could anticipate or control. This interplay generated emotional expectations and disappointments that each side consistently misread, thereby pushing the terms of debate onto a moral ground from which there could be no retreat.