Link’s predicament casts a long shadow over other China watchers. “Three or four times a month I get questions from students: How can I avoid getting on a blacklist like you?” Link said. He adds that he’s seen doctoral students avoid writing about democracy in China out of fear of the blacklist.

Jerome Cohen, who teaches Chinese law and society at New York University Law School, has similar impressions. “There are writers who I respect who don’t choose certain subjects because they will engage them in controversy with China,” he said, adding that Xinjiang, the far western province that has been the site of ethnic and religious unrest, is “certainly radioactive.” For example, several Western contributors to the English-language book “Xinjiang: China’s Muslim Borderland” (2004) were subsequently denied visas. It may not even matter what scholars actually write on contentious topics. “Visa denials seem to be based on the subject matter more than what the individual says about the subject,” Cohen said.

While Beijing’s censorship is well known, the self-censorship of Western writers is shrouded in uneasy silence. The idea that scholars “collectively are compromising our academic ideals in order to gain access to China offends people intellectually, but we all do it,” a professor at a prestigious American university told me in a telephone interview. He requested anonymity out of fear of alienating not Beijing, but his colleagues in the United States.

This caution shapes the overall body of Western books about China, which some say emphasizes the country’s economic success over its political repression. But this may also be a result of a widespread view that the Chinese model, whatever its unsavory aspects, has worked. “China is now seen as such a success,” said Ian Johnson, the author of “Wild Grass: Three Stories of Change in Modern China” and winner of the 2001 Pulitzer Prize for his reporting from China for The Wall Street Journal. “I think on a deeper level the books on China reflect the West’s deeper angst about its own position in the world, and an uncritical view on China that the Chinese themselves often don’t share.”

You can still find Western books that take a less rosy view of China, as well as critics of its government who suffer no repercussions. But Beijing’s reactions can be unpredictable, which is precisely what makes its brand of censorship so effective. Those outside China have an even murkier understanding of how it works, and as a result may end up silencing themselves the most.

Ken Chen, the executive director of the Asian American Writers’ Workshop, describes an event he held in New York for “Prisoner of the State,” the posthumously published memoir of Zhao Ziyang, the reformist Communist Party leader who was put under house arrest after the Tiananmen Square crackdown. At the event, a reporter affiliated with the religious group Falun Gong, which is despised by Beijing, asked to interview two of the book’s Chinese editors as well as an American professor. “What I found interesting and ironic,” Chen said, “is that the two Chinese editors felt free to sit in front of the camera for the interview and make some highly controversial pro-democracy statements, but the American professor refused even to be interviewed out of fear of reprisal by the Chinese government.”

Chinese writers themselves are sometimes caught off guard by Western wariness of Beijing. Yu Hua, the author of the controversial novel “Brothers,” told me that Westerners often ask why his work isn’t banned in China. “Chinese readers don’t think that my books should be forbidden; instead, Western readers have this viewpoint,” Yu said in an e-mail message.

Yu has considered various ways to respond when asked why his work isn’t banned. He said he now goes with the simplest answer: “I don’t know, either.”