There is a growing perception within the Bush administration that Soviet President Mikhail S. Gorbachev's power is ebbing, leading U.S. officials to open lines of communication to other levels of the Soviet system. Some U.S. officials are searching for ways to shore up Gorbachev's beleaguered regime, while at the same time trying to position the United States for a possible realignment of political power in the Soviet Union. ``The evidence is clear that power is now moving out of the central government to other levels, or even out of government altogether,'' said one U.S. official who agreed to discuss the issue on condition his name not be used. ``The focus now is in the republics.'' Another official said the administration is not worried - at least not at this point - about the Soviets' ability to live up to their international agreements or about any desire to change their strategic posture. International confidence in the Kremlin's peaceful intentions will be on display this week when President Bush, Gorbachev and the leaders of 32 other nations gather for the signing of a long-sought agreement to reduce conventional forces in Europe and end the military faceoff that divided East and West throughout the Cold War. The Bush administration doesn't doubt the Soviet regime's will, one source explained, but added: ``The danger is that Gorbachev may lose the ability to make decisions and carry them through.'' That official, who also spoke on condition of anonymity, said the United States is now working with reform leaders in the Russian federation, the Baltics and elsewhere, partly in hopes of shoring up Gorbachev's political standing at home. ``By helping the reform movement at various levels, we help Gorbachev,'' the official said. ``It gives us other access, more information about what's going on, plus it's neutral-to-beneficial for Gorbachev because we're supporting Gorbachev. It doesn't undermine him.'' Fourteen of the Soviet Union's 15 constituent republics have declared sovereignty or, in a few cases, their intention to seek complete independence from Soviet rule. Boris Yeltsin, president of the Russian federation, which accounts for roughly half the Soviet population, is threatening to institute his own reforms that could establish an economic system independent of the central government. The deteriorating Soviet economy is at the root of much of the public's unhappiness with the central government. In one sense, the shift of power away from the center ``is quite consistent with democratization,'' which the U.S. government has supported wholeheartedly, one analyst observed. But he added that it complicates Western efforts to support reform. ``We recognize that imbalances and uncertainty can lead to instability,'' the source said. ``There is a potential for a very high level of frustration, public indignation, a volatile situation if economic deterioration continues.'' Demonstrators from both the left and right showed their anger with Gorbachev and the economic calamity in Revolution Day demonstrations Nov. 7 marking the 73rd anniversary of the Russian Revolution. John Hardt, a specialist in Soviet affairs at the Library of Congress, said Gorbachev does not appear in imminent danger. He retains control of the police, the military and the KGB, the secret police agency responsible for state security, Hrdt noted. ``The levers of power are quite clearly in Gorbachev's hands,'' he said, adding that the Soviet leader was able to implement massive military reductions and set a new course for Soviet policy in the Middle East, neither of which could be expected to garner strong support from the military establishment or government bureaucracy. But Hardt acknowledged that Gorbachev is threatened by crises rippling through Soviet society and that his popularity inside his own country is extremely low compared to his status elsewhere in the world. ``Gorbachev's power is becoming more diffuse,'' said a State Department official, also speaking on condition of anonymity. ``But we want to be careful not to sell him short. He's shown he can accomplish a great deal, even against tremendous inertia and resistance.'' ``Time will tell,'' the source said, ``whether this master of the old political system can master the new'' one he has installed. A source familiar with foreign policy strategy discussions at the top levels of the administration said there does not appear to be an imminent threat to Gorbachev. ``There is no apparent challenger, no alternative, no reason to expect military intervention,'' the source said. ``What is more likely is that it will become harder for him to exert influence. ``To a degree, that's a natural result of increasing pluralism, and we applaud that. But what's difficult is the institutional structures have not had much time to develop, and that makes for an unstable situation.'' The United States, several sources said, is continuing to support Gorbachev while trying to establish contacts at other levels, particularly where it can encourage economic reform and creation of market forces. ``Arms control agreements still have to be negotiated at the central government level,'' one source explained. ``But we can provide technical cooperation and support economic activity at both levels.'' The Soviet republics are in some ways similar to the states of the United States in that they have government structures that mirror the one in Moscow. Under Gorbachev's predecessors, the Kremlin dictated practically all policy to the republics, but it clearly can no longer do that. Today, under pressure from nationalists and malcontents in almost every republic, it is struggling to keep the union from splintering along republic or ethnic lines while it negotiates a new balance of power between the center and the republics. The shift in power complicates the effort to back Gorbachev and his reforms, one source said. ``No one has much experience in making changes of this sort.'' ``Gorbachev's ace in the hole is that he is the only Soviet leader who has made it on the world stage,'' said another official. ``True, that doesn't put food on the table, but many realize they need the West if they're going to improve and modernize their own situation. ``Much of the Soviet leadership recognizes this, even if they don't like it. So Gorbachev has a strong card to play in foreign relations.''