Despite the presence in Moscow of a high-level Chinese delgation, now carrying on full-scale talks on Sino-Soviet rapprochement for the first time in 15 years, there is little reason for Americans to fear a resumption of the close alliance that once prevailed under-Josef Stalin and Mao Tse-tung. tThat is not in the cards.

Nevertheless, after so many abrupt changes in Chinese foreign policy in recent years, it is not surprising that a good many Americans still think the United States will ultimately come out on the short end of normalizing relations with the People's Republic.

Their anxiety springs from a lurking suspicion that, once the Chinese communists have obtained from America the kind of help they need, they will again link up iwth the Soviets, possibly in combination against the United States.

Following a meeting in Moscow with President Brezhnev earlier this year, Howard Baker, the Senate Republican leader, quoted the Russian leader as saying, "If you set two bears to fighting, you should not expect them to always fight each other." Sen. Baker said, "I assume he meant that China and the Soviet Union might not always be enemies

Up to a point, that could be the case, for logically the well-known differences between Peking and Moscow do not appear to be wholly irreconcilable. It would not be astonishing if the new Sino-Soviet talks, which are expected to be of marathon duration, ultimately lead to a limited detene, perhaps not unlike the arm's length detente between Moscow and Washington.

Such a mutual nod to mere coexistence, however, should pose no threat to Russia. Few, if any, Asia experts believe the Chinese and Russian negotiators will achieve much more than a relaxation of tensions, which is in everybody's interest, although a long way from reviving the 1950 Sino-Soviet friendship and mutual defense treaty that Peking terminated several months ago.

The seldom-mentioned reason Peking has no intention of again embracing Russia has more to do with national egoism, in its most compelling sense, than with diplomatic considerations. During the uneasy Sino-Soviet alliance, the Chinese discovered the hard, humiliating way that being a partner with Russia really amounted to being a puppet, or at best a subservient junior partner. The universal feeling in China today is: never again.

Even as the rapprochement talks were getting under way in Moscow, the Chinese vice premier, Deng Xiaoping, spelled this out to Canada's former prime minister, Pierre Trudeau. Deng, according to Trudeau, "made it quite clear that in his mind of differences between Moscow and Peking have their origin in Russian chauvinsim that is worse, as he put it, than in czarist days." Another high Chinese official put it even more bluntly. "You can't accept help from the Russians," he told me, "without their trying to run you. You've got to knuckle under, or else. We've had enough of capitulation."

The Chinese leaders can afford this independence because, having over-come the xenophobia encouraged by the late Mao Tse-tung, they can now get from the United States, Europe and Japan the economic and technological aid they so acutely need without the kind of strings imposed by Moscow.

The Soviet Union and China share the longest condiguous border (4,500 miles) in the world. Their hostility is historial, going far back to czarist expansion in the Far East and in Central Asia at the expense. Their alliance in the 1950s was a brief and unhappy one. Since emancipating itself from Russia, China has insisted that its form of communism is the correct one and that China, in the words of Wolfram Eberhard, "should be the leader of the communist world, not Russia, which has 'deviated.'"

In contrast to the hatred and distrust reserved for the Russians, the Chinese now warmly welcome such old antagonists as the Japanese, British, French and Americans, despite their past imperialistic interventions in and exploitation of the Middle Kingdom.

Visitors from these countries are openly applauded wherever they go by both adults and children. It's similar to the way the United States has embraced the Japanese and the Germans despite World War II.

Veteran Asian diplomates believe it would be in America's long-range interest not to play off China against Russia, but to encourage the development of a triangular detente among the two current superpowers and the super-superpower that China seems destined to become in the not too distant future.

The word from Moscow is that its realistic aim is not so much to end all Sino-Soviet differences as it is to contain them. In proposing the new talks, the Russians suggested an agreement putting relations on a basis of "peaceful coexistence, mutual respect for sovereignty and territorial integrity." That would be a lot in itself.