In judging Zhang's credibility, we are asked to rely on the credentials of the three men who are vouching for Zhang's book -- and those credentials do carry extraordinary heft in the worlds of journalism and academia. The only physical evidence that Zhang exists was a silhouetted interview he granted CBS News' "60 Minutes" in early January and an interview he granted the New York Times. In that interview, Zhang told his interlocutor: "We believe that only the Communist Party has the ability in China to carry out political reform ... In this sense we are not dissidents trying to operate from outside the system."

Critics and China experts have approached "The Tiananmen Papers" cautiously, some doubtful of its authenticity, others cautiously optimistic. No one, it seems, is taking these papers as a matter of historical fact -- at least not without adding the obligatory qualifiers. The passages whose provenance raises the most questions -- and they are often the most interesting -- are quotes taken from private meetings at his residence between Deng, who essentially served as the shadow leader of China at the time of the Tiananmen crisis, and senior members, both active and retired, of the Communist Party. Zhang, in what appears to have been an epic breach of Zhongnanhai security, apparently had considerable access to people who had considerable access to these leaders.

The past century has seen some prominent forgeries, and both publishing houses and journalists have been duped time and again -- a fact that Schell acknowledges in his afterword. And one of the more famous fakes came from China. Sir Edmund Backhouse discovered a diary in the home of Jing Shan, an assistant to the imperial family, which later became the basis for his book "China Under the Empress Dowager" early in the early 1900s. But years later, confidence in Backhouse's reputation has been stained by lurid tales (including insinuations that he had necrophiliac sex with the corpse of the Empress Dowager, according to Time magazine) and faith in his account has faded. The Oxford-trained academic didn't help his cause by failing to ever produce a copy of the diary.

The jury, meanwhile, is still out on the 1983 book by Yao Ming-Le, "The Conspiracy and Death of Lin Biao -- How Mao's Chosen Successor Plotted and Failed: An Inside Account of the Most Bizarre and Mysterious Event in the History of Modern China," which claimed that Marshal Lin Biao, a protege of Mao, was murdered for plotting to kill the Chinese leader. Last year, the daughter of the commander of the Chinese air force at the time of Biao's mysterious death, Jin Qiu, stated that after conducting her own investigation, she concluded that the book was pure innuendo. "Few students of the subject have taken this version seriously," she wrote, "chiefly because the sources to which Yao claimed to have access were never made available to others." Jin fell short of outright disproving the account, but she did successfully raise fresh doubts about its legitimacy.

"The Tiananmen Papers" is a different story. Strong contextual evidence suggests that it is legitimate. It has long been known, for example, that Deng Xiaoping had orchestrated the ouster of Party General Secretary Zhao Ziyang, his anointed successor, because he had been too soft on the students. Deng retired from the Politburo in 1987, and his only official role in the government was that of chairman of the Military Affairs Commission of the party. It was widely reported that Deng was in fact running things even after the appointment of Zhao. But it was never before known how deep a role he played in the day-to-day decision-making about Tiananmen. The dissident writer Liu Binyan told the New York Times of deep splits in the Communist Party less than two weeks before the June 3 massacre; he also referred to dissent within the military, which is corroborated in "The Tiananmen Papers."

After his meeting with Deng in May 1989, just weeks before Tiananmen, Mikhail Gorbachev was bitterly criticized by Chinese officials for revealing to the foreign press that Deng was still calling the shots. But only with "The Tiananmen Papers" does the full story of Deng's involvement emerge. The power struggle between Zhao and Prime Minister Li Peng was also hinted at in media coverage of the student uprising in 1989. But "The Tiananmen Papers" are the first to document the Politburo split behind the clash.

"The Tiananmen Papers" takes us back to March 1989, when the Chinese government became conscious of the growing public dissent that would result in the student movement. "The national mood reflected a profound questioning of China's leaders, political system, and direction," an intelligence report cited in the book states. "But it was hard to tell whether the social contract was breaking down as a result of inflation or corruption, or a normal civil society was emerging as a result of prosperity and liberalism." The papers cover the period ending in the clearing of Tiananmen Square, with behind-the-scenes details assembled from Xinhua (China's official press vehicle-cum-spy shop), meeting transcripts, notes from telephone conversations and private conversations between the country's highest leaders.

Though Schell says there's no "smoking gun" in the documents (a fact that he says increased his belief in their authenticity) there is plenty of potentially live ammo. It has long been known that there were ideological splits at the top of the Communist Party. But what wasn't known prior to the documents' release was how deep this rift had grown during the student uprising.

"The Tiananmen Papers" depicts Party Secretary Zhao as a moderate figure, sympathetic to the demands of student protesters. Zhao tried to steer his fellow leaders away from declaring martial law and toward dialogue with the students. Prime Minister Li, on the other hand, comes across as an obdurate hard-liner. Deng's trusted confidante, he feared that the student uprising promoted the "bourgeois liberalism" so despised by dyed-in-the-wool Leninists and posed a serious threat to the Chinese government. A power struggle between Li and Zhao ensued. Li, who still serves on the Politburo Standing Committee but who is widely disliked both in and outside of China since the Tiananmen massacre, probably stands to lose the most from the publication of the "Tiananmen Papers," since they show that without his cheerleading for the crackdown, the events of June 3 might never have happened.

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