Many of the 1989 movement's most famous leaders fled, like Wu'er and Wang, to the West. Several enrolled at U.S. universities. A few continued to advocate for human rights from abroad. Others went into business. Wu'er now manages an investment fund in Taiwan. After earning an M.B.A. from Harvard University, Chai Ling, another student leader, started a Boston software company that provides free Web portals to universities in exchange for students' contact information, promoting its product with press releases that invoked her role in the square. (Chai has also filed suit against the makers of The Gate of Heavenly Peace, who include several prominent China scholars in America, for linking on their Web site to news articles that reported critical information about her company.)

But outside of labor camps and Western democratic havens, the memory of what happened dulled. For a few years following 1989, videos about June Fourth — known in Mandarin simply as liu si, or "6/4" — circulated on the black market. Then the government began a campaign of forgetting, first spinning the event and then erasing it. The popular Chinese search engine Baidu now blocks at least 19 derivations of "six four," including Chinese character homophones, the abbreviation "sf," and "63+1."

Such controls are far from total, but they can be very effective. On June 4, 2007, a newspaper in Chengdu published a small advertisement recognizing the mothers of the 1989 victims. Online, chat-room users speculated about how such a message could have gotten past the paper's editors — until it was revealed that the young clerk who took the ad didn't recognize the event. What might have been a quiet act of resistance was instead a measure of a nation's forgetting.