PARIS -- When Moammar Gadhafi recently released a French woman held hostage by the Libyans for two years, the French government handsomely praised this act of appalling cynicism as a ''humanitarian'' gesture.

With an unconscious but exquisite sense of symmetry, Marlin Fitzwater now uses the same word to applaud China's decision to release its most famous hostages, Fang Lizhi and his wife, Li Shuxian.

Rejoice that Fang and Li have been airlifted out of harm's way to exile in Britain. But do not join Fitzwater, the voice of George Bush, in granting the Chinese Communist regime a Good Housekeeping Seal of Approval. The White House spokesman's verbal bow to Beijing rewards hostage-taking just as surely as did France's hosannas for Gadhafi.

The Fitzwaterian slip does put the ''humanitarian'' Chinese leadership in the right league internationally, up there with the Libyan lunatic. But praising Beijing for freeing people who should never have been the target of official persecution in the first place debases the language and practice of American diplomacy.

Only the infirm rulers of Zhongnanhai Compound, the Kremlin of Beijing, know why they chose this moment to allow Fang and Li to leave the U.S. Embassy, where they had taken refuge last June. But it is worth noting that the dissident couple was freed scarcely two weeks after the Bush administration took its first concrete step to show displeasure with the situation in China.

This occurred on June 7, when Vice President Quayle met for an hour in the White House with Chai Ling, the young woman who played a key role in organizing the Tiananmen demonstrations and then had to spend 10 months in hiding in China before escaping abroad. Like Fang, she has been labeled by Beijing as ''a counterrevolutionary criminal'' for calling for democracy in China. The Quayle meeting is the kind of language -- okay, pressure -- that Deng Xiaoping understands, as I suggested in a column April 17 that urged the Bush administration to listen to Chai and other Chinese dissidents.

The Quayle-Chai meeting stunned Beijing, informed diplomatic sources tell me. It got across the message that even Bush's seemingly boundless store of patience with his Beijing comrades had a limit. In all likelihood, the show of U.S. firmness -- not the long period of U.S. kowtowing that preceded it -- got the Chinese leaders to finally honor the promise they gave last December to Brent Scowcroft, Bush's National Security Council adviser, to free Fang and Li.

The Chinese had demanded that Fang and Li sign confessions admitting treason. But they refused and now have been freed without submitting to this dangerous humiliation. Even the official Chinese statements on their release claim no more than that Fang and Li admitted to having criticized China's Communist leadership. Again, firmness worked with Beijing.

There is one drawback to the liberation. The Chinese appear to have insisted that Fang go to Britain rather than to the United States or France, where Chinese dissidents are active. Margaret Thatcher's government, more worried about Hong Kong than democracy in China, will make sure Fang and Li remain, shall we say, discreet. China has lost a powerful voice for change, as well as its most eminent scientist and sage.

The flight to Britain ends a year-long nightmare for the couple. I happened to witness it as it began. In Tiananmen Square I had come to know one of Fang's friends, Jonathan Mirsky, the China correspondent of The Observer newspaper of London. Mirsky, a fluent Mandarin speaker just named Britain's journalist of the year for his dispatches from Tiananmen, helped me understand the historical and social context of the student uprising last May and the brutal repression that followed. When Mirsky and I went to meet Fang and Li on a late May afternoon as the demonstrations had reached their peak, the victory of the Stalinist hard-liners over the reformers became clear.

We had phoned that morning. By the time we arrived, the couple had learned of a list of intellectuals and activists to be ''dealt with'' when the army put down the demonstrations. Fear physically transformed Li, whom Mirsky barely recognized when she opened the door to the apartment. She trembled as she stood in the vestibule and said they could not talk now. She stammered out a reference to the list. She begged us not to say we had visited them, so fearful was she of government reprisal. This anxiety a few days later drove them into the U.S. Embassy in justified fear of their lives.

The going into exile of Fang Lizhi and Li Shuxian is no cause to praise their oppressors. Nor should it cause the World Bank and the Group of Seven industrial democracies, who meet in Houston in July, to conclude that now is the time to relax the pressure that has been brought to bear on China. Firmness, not kowtowing, brought this liberation.