Fang Lizhi's departure for a safe haven in Britain leaves China without a prominent dissident with the courage and stature to speak out against the government. A year after tanks crushed the pro-democracy movement, China has effectively silenced all open dissent through arrests, intimidation and forced exile. Fang refrained from speaking out during his year of refuge in the U.S. Embassy in Beijing. But as long as he stayed in China _ outside the grasp of a government that sought to try him as an instigator of unrest _ he remained a symbol of resistance to political oppression. Now the 54-year-old astrophysicist and his activist wife Li Shuxian join a growing list of dissidents who have escaped the country or been banished. Most have been frustrated by lack of funds, poor organization and an inability to make their voices heard where it counts _ at home in China. The decision to allow Fang and his wife to leave the country came one week after China similarly dispatched another well-known advocate of democratic reform, Taiwanese singer Hou Dejian. Hou, who defected to the mainland from Taiwan in 1983, played a key role in negotiating the evacuation of students from Tiananmen Square during the June 4, 1989 military assault theat crushed the pro-democracy movement. He hid in the Australian Embassy for two months before the Chinese promised he would not be arrested, emerging to become one of the few Chinese willing to openly criticize the government. Hou and two other companions from Tiananmen _ activists Gao Xin and Zhou Duo _ finally went too far when they tried to hold a news conference for foreign journalists on May 31 to call for the release of political prisoners. All three disappeared hours before the news conference. Police released Gao and Zhou, who had previously spent months in prison, after the anniversary of the June 4 crackdown had passed. But Hou was taken out to sea, put on a Taiwanese fishing boat and returned to Taiwan. Also Monday, China announced that another dissident arrested last summer, Wang Xuezhi, was being released from a Canton prison and allowed to go abroad to rejoin his French wife. China appears to have concluded that exiling dissenters such as Fang and Hou serves both to ease Western criticism of China's human rights record and diminish their ability to influence opinion at home. Those who left or escaped after the military crackdown _ people like student leader Wu'er Kaixi, political scientist Yan Jiaqi and entrepreneur Wan Runnan _ say they fear the world is gradually losing interest in China. Liu Binyan, a journalist and maker of film documentaries who has been living in exile in the United States for two years, said in a recent interview that he longs to return home, but thinks he might face arrest. ``This is a very important time in China,'' he said. ``I want to go back and experience everything myself. Even if I can't write about it.'' Those released from prison in recent months as China seeks to improve its image abroad have sought the safety of silence. Almost all, under police orders, have avoided political activities and stayed away from foreign reporters. ``Coming back home was like a dream,'' said journalist Dai Qing when she was freed in May after being imprisoned for 10 months. But Dai, one of the free spirits of China's tightly controlled mass media, said she could say no more. Speaking to a foreign reporter without permission would mean a return to prison.