AS COLUMNS OF smoke rose from Tiananmen Square and tanks took up positions along Beijing’s central thoroughfare, it was hard to imagine the Communist Party celebrating its 100th birthday still firmly in charge. It was the day after the army had slaughtered hundreds, if not thousands, of people on June 3rd-4th 1989. The massacre had crushed a nationwide pro-democracy movement. But the city seethed with anger. How could that fury remain bottled up for ever?