Ten years have passed since Richard Nixon dramatically ended an era of American hostility toward the People's Republic of China. The excitement that surrounded his historic visit to Peking is now a matter of memory. But the benefits flowing from a normalization of ties continue to grow and to remind both sides that, whatever the strains of the moment, the relationship is worth cultivating.
Fortunately, Peking and Washington agree. While the anniversary is not being marked by fireworks, President Reagan and Prime Minister Zhao Ziyang have exchanged letters which are described as the most cordial since the dispute escalated over United States arms sales to Taiwan. That may not be saying much, but the Chinese leader's promise to work with the United States to try to overcome the present deadlock suggests there may be a degree of flexibility in Peking's position which is not evident from its public posture.
Given the depth of China's feeling about Taiwan, however, it seems clear that the United States will have to be more forthcoming. The heart of the problem lies in the ambiguities surrounding the question of Chinese sovereignty over Taiwan. The Shanghai Communique issued at the end of the Nixon visit and the joint communique signed upon the establishment of diplomatic relations in 1979 are deliberately vague on this point.
Mr. Reagan has reaffirmed the two communiques, signalling that he recognizes the importance of the strategic relationship. That is a welcome step given the vehemence of his support for Taiwan during his election campaign. But, if Sino-American ties are to be steadied, he may have to find some formula that more explicitly recognizes China's sovereignty over Taiwan -- in principle, of course, not in present actuality. Realistically, Peking has no hope of trying to take Taiwan by force -- a move which would invite American military action. It has taken pains in fact to stress that it seeks only ''peaceful reunification'' of Taiwan and the mainland.
But, as such respected scholars as Doak Barnett point out, China is concerned about the general trend of American policy on arms sales to Taiwan. Some assurance may be needed from Washington both on the matter of long-term weapons transfers and on not implicitly supporting the Taiwanese posture of ''never'' talking with the Chinese communists. Certainly Mr. Reagan risks a deterioration of Sino-American relations if he does not find some compromise which, while it might not actually solve the problem, could satisfy Peking's concerns and buy time.
This sticky problem should not be allowed to obscure the gains of the past ten years, however. For the United States, improved ties have meant converting China from a threatening to a friendly power in Asia, with all the benefits this yields in terms of US military requirements in the region and better relations between China and most of its neighbors. They have served as a useful diplomatic counterweight to relations with the Soviet Union. They have led to a sturdy trade and cultural and other contacts. Not least of all, they have helped reinforce the leadership of Deng Xiaoping and the priority he has given to modernization of the country instead of to military development.
These are enormous gains which no US administration can afford to regard lightly. The Sino-US rapprochement launched a decade ago has proved mutually beneficial, and the challenge for President Reagan is to avoid an impasse over Taiwan which could wreck that burgeoning relationship. The high-drama events of February 1972 may be forgotten. Their significance should not be.