With the emergence of China's new active global policy symbolized by Communist Party-Chairman Hua Ku-Feng's current European trip, the Soviets appear to be alarmed by what they see as an extremely grave challenge to their interests.

Soviet fears and anxieties are based less on China's capacity to effectively counter Kremlin positions, although ranking Soviet officials indicate concern in private conversations.

The real source of alarm is the possibility of Sino-American cooperation or even tacit understanding which is viewed here as a prospect of significant switch in the strategic balance at Moscow's expense.

Such a development would be viewed as a mortal blow to detente since it could isolate the Soviet Union and force it to increase military spending at a time when the Kremlin is beginning to focus on the improvement of living standards at home and facing growing pressures to satisfy popular demand for a better life.

Soviet hostility is so widespread that even in conversations with ordinary Russians one frequently hears the term "yellow peril" accompanied by warnings that Americans should not be taken in by Chinese policies and that ultimately Europe and North America would have to contain Chinese "expansionism."

Soviet officials do not use racist terminology, but they do not hide their concern that the Carter administration may be tempted by the opportunities afforded by China's new and broad challenge to Moscow.

These official argue that China's warmth toward the West is tactical maneuver with the aim of damaging Soviet-American relations and ultimately provoking a confrontation between the two superpowers.

Should Washington be tempted to play "the Chinese card," according to this line of thinking, the Soviet Union would be weakened temporarily but a greater long-term damage would be inflicted to American interests as a result of a profound change in bilateral relations that would ensue.

Similar views are presented in the officials press which has mounted a propagadan campaign against the Chinese that is unmatched in its bitterness since the days of Sino-Soviet border clashes in 1969.

A commentary yesterday's Literaturnaya Gazeta addressing the possibility of Sino-American collusion includes the following description of the Chinese leaders and their policies:

"Their lack of political principles, their duplicity and cynicism, are known to the whole world. A rapprochement or alliance with them represent risks for everyone. Their reliability is deceitful. Perfidious stabs in the back are their way of operating. It is a shortsigted view if one believes that they could be pacified. Their covert objective is to provoke a military conflict between the United States and the Soviet Union and this is a permanent part of the basic Maoist doctrine aiming to establish world hegemony. The final play of the Chinese card (would permit) Peking to turn it into catastrophe for the entire humanity."

Underlying Soviet concerns about Peking's new diplomacy is a deep suspicion that the Carter administration may move toward normalization of relations with China and thereby increase the level of danger on Moscow's eastern flank.

Security problems in the region have already been multiplid with the conclusion of a Sino-Japanese friendship pact last week. Tokyo and Peking also agreed to oppose the efforts by any thrid country to establish "hegemonty in the Asia-Pacific region" - a clause seen here as freeing Chinese hands to become more active in Southeast Asia.

Hua's visit to Romania, which is a member of the Warsaw Pact, and Yugoslavia, a nonaligned Communist country, seems to the Russians to be more than an ideological challenge.

It shows the emergence of a China less preoccupied with itself and more involved in mischief on Moscow's flanks.

In Soviet eyes, the chief villain of this new policy of "encirclement" is Zbigniew Brzezinski, President Carter's national security adviser, who is deeply distrusted and who is believed to have encouraged the Chinese to actively counter their Communist rivals.

But Peking's ambition to create a broad "united front" against Moscow becomes a matter of fundamental concern here only if it is accompanied by normalization of relations between Washington and Peking.

Peking's ideological challenge and its active challenge to Soviet pretentions to the leadership of the Communist movement are irritants that do not require drastic policy departures. A Sino-American collusion, however, would be of such overwhelming concern here that it would lead to both foreign policy and domestic adjustments, according to the officials speaking privately.

What these officials are suggesting is that Washington may share temporary strategic interests with Peking, but the long term U.S. interest lies in cooperation with the Soviet Union in securing a stable international environment.