BEIJING -- The rapid demise of the Communist Party's hold on the Soviet Union represents one of the worst nightmares of the aging hard-liners obsessed with maintaining their firm control over China.
The new impetus for further reforms in the Soviet Union, for greater independence for its republics and for eliminating the Soviet Communist Party's power only confirm the Chinese leadership's long-standing fear that the changes begun by Mikhail S. Gorbachev threaten the future of orthodox socialism in China.
Since consolidating their power with the bloody crackdown on the Tiananmen Square protests in June 1989, China's hard-liners have continued cautious economic reforms but above all maintained iron-fisted political control by the Communist Party.
They repeatedly have warned that world communism is engaged in a life-or-death struggle with an American-led, capitalist plan to subvert socialism, an alleged plot they have labeled "peaceful evolution."
And China's leaders have been particularly worried that the Soviet Union's moves toward political freedoms and decentralization would spill over the nation's 4,000-mile border with the U.S.S.R., encouraging Chinese political reformers and aggravating independence yearnings in such areas as Tibet, the Xinjiang Autonomous Region and Inner Mongolia.
"This leadership has imagined all kinds of scary scenarios coming from the Soviet Union fairly often in the past, from civil war to ethnic independence movements," said a European diplomat. "Now some of that's coming true, and they certainly must be really scared.
"Those who hold power are going to conclude that they've been right all along and that they must now do everything possible to avoid happening here what happened in the Soviet Union, even if that means bringing out the tanks again as they did in Tiananmen Square," the envoy said.
"They're going to ask themselves, "Have we done enough to keep the lid on," the diplomat said, "And their tendency will be to tighten the screws here even more."
Early last week, in response to the uncertainties posed by the sudden ouster of Mr. Gorbachev, China's People's Liberation Army was put on a low-level alert in the Beijing area and along China's border with the Soviet Union, a Western diplomat said.
Other Westerners have noted in recent days a slightly increased presence of armed policemen in Beijing. And diplomats also anticipate that the focus on "peaceful evolution" in workers' and the military's political-study sessions is apt to intensify in the near future.
But otherwise, there has been virtually no overt reaction so far from either China's leaders or its people to the failure of the coup against Mr. Gorbachev.
"As the news spreads, more and more Chinese people are going to start asking some critical questions that are going to pose challenges to the leaders," another Western diplomat said.
"But it would be a fantasy to suggest that the Chinese people now are going to get out in the streets and try do what the Soviet people have done."
Many Beijingers, in fact, do not seem to fully understand what took place in Moscow.
"Many people are confused about the political factions in the Soviet Union," said a student who participated in the 1989 Tiananmen Square protests. "And even if they did understand it, the conditions here are still not ripe for them to react in a public way."
When the coup first took place, Chinese newspapers and TV news programs gave prominence to the statements of the Soviet hard-liners who claimed power.
When it failed, there were only terse reports of Mr. Gorbachev's comeback, reports that were much less prominently played and gave no explanation.
There has been no official news here of Muscovites' protests, and the only mention of Russian President Boris N. Yeltsin's bold resistance to the coup was in reporting that his decrees had been declared illegal by the coup leaders.
Although China officially maintained throughout the crisis that the events were solely the business of the Soviet people, the Chinese leadership's message was clear: China would have been more than pleased if the hard-liners had succeeded in deposing Mr. Gorbachev.
Diplomats here agree that this stance for the time being will have little substantive impact on Sino-Soviet relations, which have been steadily improving since Mr. Gorbachev's visit here two years ago and which are primarily geared to each nation's respective security interests.
But some believe that the border talks and military exchanges that have steadily taken place this year will now be infected with a renewed sense of distrust between the two countries.
"Despite China's official statements, the Soviets know damn well what the real position of the Chinese leadership was," a Western diplomat said, "and they're going to show China very little warmth."