Sino-American relations have been on a roller coaster for the past generation. In World War II and its immediate aftermath, America somewhat sentimentally tried to promote a weak China, torn by civil war, to great-power status. Then, with the Chinese revolution and the Korean war, came a swing to the other extreme of seemingly permanent hostility, with contact between the two countries to all intents and purposes broken off. When a rapprochement finally took place in the early 1970s, many Americans fell prey to our nostalgic national habit of equating relations among states with relations among people and endowed it with qualities of personal friendship.

In the nature of things, this raised exaggerated expectations that could not be fulfilled. Almost inevitably, strains have developed. To some extent occasional squabbles are a sign of maturation, of a normal relationship between countries. Still, the tensions in recent years have gained their own momentum, threatening to damage the important common long-term objectives of both countries.

It is to reverse this process that Secretary of State Shultz has set out on his journey.

Conventional wisdom has it that the current difficulties are largely due to the clumsiness of the Reagan administration. To be sure, some of the exuberant early statements on Taiwan will not be landmarks in the annals of diplomatic finesse, and the unpropitious timing of the textile issue just prior to the Shultz visit makes one wonder about the coordinating mechanism in our government.

The fact remains that the administration has gone to extraordinary lengths--even more remarkable given its starting point--to emphasize its commitment to close ties with Peking. And it took two to make the textile issue intractable. The causes of the strains in Washington- Peking relations go deeper; they antedate the Reagan administration; they have been exacerbated in both countries by errors of judgment and domestic conflicts.

These strains originate, indeed, in the two countries' differing approaches to foreign policy. During the early period of renewed contacts, much innocent nonsense could be heard about how "unnatural" had been the estrangement between the American and the Chinese peoples, as if rapprochement fulfilled a deep emotional necessity on both sides. The facts were far more prosaic. China, in its marvelous history of 3,000 years, has never had the experience of dealing with other societies on the basis of equality. It has felt most comfortable when able to be aloof, self-contained, as a culture whose uniqueness placed it beyond the reach of outsiders.

For China there was nothing at all unnatural about living apart from America. Nor can it be said that in 1971 there was a groundswell of grass-roots demand in the United States for an opening to China.

What brought the two nations together was not sentiment but awareness of a common threat. The Chinese saw an awesome buildup of Soviet military power along the border, including nuclear missiles and 40 modern combat divisions. By 1969, it was obvious to China that Marxist theory not only did not shield it from military pressures; on the contrary, the newly promulgated "Brezhnev doctrine" claimed the right to enforce the unity of the Communist world by military might.

For the United States, opportunity combined with necessity. The expansion of Soviet military power and constant Soviet pressures on the international equilibrium had been for us a familiar feature of the postwar scene. But it was only in the late 1960s that the United States began to sense the limits of its power and to recognize the need for associations beyond our traditional allies. The process was given impetus by a sophisticated president to whom an unsentimental perception of power relationships was congenial rather than anathema. There were powerful incentives for a rapprochement with China: to balance the Soviet Union, either to restrain it or to induce it to negotiate seriously; to isolate Hanoi to give it an incentive to end the Vietnam War; to maintain American self-assurance amid our messy withdrawal from Indochina by demonstrating our continuing capacity for major positive initiatives.

The new links between China and America flourished so long as the two sides kept their eye on the common objective of resisting what their communiqu,es came to describe as "hegemony." Simply put, this meant resistance to Soviet attempts to overturn the global balance of power and some agreement on an appropriate strategy to achieve this end.

There were inevitable differences in tactical perspective. In the developing world, Peking often relied on competing with Moscow in appealing to radical movements, which led it to back some leaders and causes that were hardly America's favorites. Also, China was leery of Washington's relations with Moscow, explicitly fearful that d,etente would undermine the West's willingness to stand up to the Soviet Union, implicitly suspicious that it might lead to a U.S.- Soviet arrangement at China's expense.

These differences were downgraded early on because each side had an interest in rapid and visible progress--the United States to demonstrate its new options amidst the frustrations of the Vietnam war; China to discourage the Soviet Union from attempting to apply the "Brezhnev doctrine" to it. Thus both sides strove to achieve a coordination of purposes if not of policies. High-level Chinese-American meetings were unique in that they rarely concerned concrete or technical negotiations; most of the conversations dealt with basic geopolitical assessments, projections and strategies. In the touchy field of Washington's relations with Moscow, the United States took great pains to keep Peking fully informed. In this manner, tactical differences were kept in perspective and not allowed to harm the essentials of Sino-U.S. relations. In that process, interestingly enough, our relations with the Soviet Union prospered as well.

The succeeding years made this mutual restraint increasingly difficult to maintain. Domestic upheavals preoccupied the leaders of both countries and spilled over into foreign policy. At first, relations with Moscow were at the heart of the problem. The United States always had a difficult passage to navigate: if Washington grew too exuberant about d,etente, we would disquiet Peking and stampede it into its own overtures to Moscow in order to avoid being left at the gate. If we were too intransigent, Peking might take our counterbalancing of Moscow for granted and be tempted to flaunt opposition to us on bilateral issues or in some areas of the world without fear of being left alone with the Soviet Union.

The Carter administration oscillated between both extremes. The Vance wing gave clear priority to improving relations with Moscow; the Brzezinski wing spoke of a "China card" as if Peking were a weapon in our arsenal. But a card can be discarded as well as played; the unintended consequence was the unnerving inference that, for the right price from Moscow, we might loosen our ties with Peking.

The Reagan administration suffered from no such ambivalence. Its anti-Soviet pronouncements seemed to freeze us into a rigid hostility toward the Soviet Union, which freed China to adopt, at little risk, a militant Third World posture of "a plague on both your houses." At the same time, some members of the new administration expressed philosophic convictions very different from those of their predecessors with respect to China itself and its relationship to Taiwan, causing Peking to fear (incorrectly) a regression to the Dulles era.

Nor is the fault all on the American side. Since the first American visit to China, Peking has experienced major domestic upheavals of its own. It would be astonishing if China's internal political battles remained confined to the publicized issues. Inevitably, some of the stridency in the reaction to American policies reflected, at least in part, factional rivalries exploiting the presumed embarrassments of Chinese leaders at not obtaining greater or more rapid concessions from the United States. In recent years, the Taiwan issue--which is genuinely neuralgic for the Chinese--has nevertheless been pursued with extraordinary stridency, even after the Reagan administration had gone out of its way to emphasize the priority it attached to Peking. No president could have conceded more than Reagan did in the August 1982 communiqu,e. Nevertheless, the Chinese assault on him inexplicably continued for many months. The ambiguous rapprochement with Moscow as well almost surely grows out of some internal maneuvering in the People's Republic--perhaps an insistence by the armed forces on some diplomatic respite so long as the Chinese military buildup receives such a low domestic priority.

Whatever the cause, U.S.-Chinese relations are less good than they should be, given the enduring parallel interests of the two countries in maintaining the global balance of power.

A stock-taking on both sides is overdue.

The real story of Secretary Shultz's visit to China will not be the familiar issues, such as Taiwan, trade and normalization. At stake will be something intangible: the way the United States and China view their respective roles on world affairs and, above all, whether these views can be harmonized. And this trip is of enormous importance. It is crucial above all to be clear about what cannot be accomplished and should not be attempted.

The Shultz visit cannot finally resolve the Taiwan issues. In the Shanghai communiqu,e of 1972, the accord on normalization of 1979 and even more explicitly in the communiqu,e of 1982, the United States has repeatedly committed itself to the proposition that there is only one China and that it would not support any variety of a two-China solution. Moreover, the United States has already recognized Peking as the government of all of China. In the process, both sides have had to make painful adjustments on such issues as American arms sales.

The future of Taiwan must now be left to historical processes, and for the Chinese on both sides of the Taiwan straits to work out in their own subtle ways as Chinese leaders themselves have affirmed. What remains for both sides is to live up to the letter and spirit of existing undertakings. The secretary will surely hear Chinese views as to what that spirit entails. But formal diplomacy has exhausted the subject; the legal framework cannot be stretched further.

Nor would the subject of trade by itself warrant a trip to Peking by the secretary of state. To be sure, trade and technology will become increasingly important to China (the speed of its modernization will depend on it). Both sides have real complaints: Our tactics in the recent textile nogotiations have been execrable. Chinese bureaucracy can be maddening for American investors and companies to deal with. We have been too slow in fulfilling promises on technology transfer. The Chinese have changed their economic plan repeatedly in recent years.

But at the heart of these issues--and the reason they fester--is the inadequate political priority that U.S.-Chinese relations have received from both sides. Neither country can want to-- nor afford to--win these battles. Both have a stake in overcoming bureaucratic inertia and suspiciousness. It is high time for the top leaders of both countres to address once again the fundamental dimensions of the relationship and to lift discussions to the strategic plane.

Above all, the United States should show no nervousness over Sino-Soviet negotiations. A mature relationship between the United States and China can only be based on the premise that each side is quite able to assess its own national interest without outside instruction. Washington and Peking regulate their relationships with other countries not as a favor to each other but to serve their interests in peace, security and progress.

If each side is wise, it will not deliberately jangle the nerves of the other by invoking a Soviet option. China is entitled to ease tensions with its northern neighbor if it can--just as we are trying to do--but it must avoid doing so in a way that makes Moscow the arbiter of both European- American and Sino-American relationships. Each side's freedom of action is in the end restricted by a set of truths that each ignores at its peril:

First, it is a preeminent strategic interest of the United States to prevent Soviet domination of the Eurasian landmass--the much-stressed hegemony--for that would shift the global balance of resources and power irreversibly to Moscow's advantage. A threat to the security of China would undermine the global equilibrium as surely as Soviet domination of Europe. And a weakening of America would jeopardize the security of China. Statesmen can make use of these facts; they cannot uninvent them.

Second, China realizes--even when it does not avow--that its frontier of over 4,000 miles with the Soviet Union is its fundamental security problem. As China modernizes, it turns into a potential long-range danger for Moscow, if only because it will be less and less subject to intimidation. Peking knows very well, moveover, that it is being wooed because the United States is in play; in our absence it might be threatened. Just as the United States--if it is rational--cannot push U.S.-Soviet d,etente to the point of endangering Chinese security, so China, if it is farsighted, cannot wish to forfeit America's vital interest in its security and territorial integrity.

Still, reality is not self-implementing. In America, each new administration proudly proclaims the failure of its predecessor and its determination to start afresh-- oblivious to the fact that this must unsettle all leaders who have staked their country's fate on the previous dispensation. The Chinese approach is patient and aloof; the Middle Kingdom has a horror of appearing as a supplicant. Washington acts as if good faith and bonhomie supply the lubricant of international relations. Peking assumes that its interlocutor has done his homework and will understand subtle indirections; the Chinese approach can therefore appear impersonal, even condescending. To the Chinese, Americans often appear unstable and slightly frivolous. To Americans, Chinese occasionally present themselves as either inscrutable or uncommunicative.

Thus both countries need to understand each other's psychology better and to establish the confidence that this understanding will last. We have to face the fact that the Chinese have developed serious doubts about our political or even emotional stability. At one point we seemed to invite military cooperation and then backed away. We promised cooperation on transfer of technology and in effect reneged. All this raised doubts whether we were really interested in a close relationship. Even where Peking acknowledges our commitment to maintain the balance of power, doubts have developed whether we are able to interpret it correctly in concrete circumstances or act on our interpretation.

When the United States is perceived in Peking as an inadequate guardian of the equilibrium, as it was over Angola, Ethiopia, Afghanistan and Iran, there are two consequences: Peking is tempted toward Moscow despite all its suspicions, if only to gain time. And the bilateral issues of Sino-American diplomacy--like Taiwan or trade--must carry a disproportionate burden of the relationship.

Chinese policy and rhetoric of the past few years have made their own contribution to the impasse. It does not build confidence to urge the United States into a defense of the balance of power and then give it equal billing as a threat to peace with the Soviet "hegemonist." In recent years the vocabulary of criticism from Peking has been far more prevalent than that of cooperation. Peking must understand that only a relationship built on some strategic understandings and cooperation on some international issues will command American public and congressional support for the long term. We cannot sustain indefinitely a relationship that in the public mind consists of constant irritation over Taiwan, some economic links (perceived as helping China more than us), and rhetorical battles in international forums.

Secretary Shultz--I am certain--will seek to make clear that we view the world in geopolitical terms relevant to Chinese perceptions. There are several areas in which Chinese and American views should be harmonized, or at least the range of our disagreements understood. First, of course, is policy toward the Soviet Union in general. In addition, we should maintain a continuing intimate dialogue on specific international issues:

* Where United States and Chinese interests converge and what may be done to concert our actions--for example, Afghanistan and Indochina.

* Where we have divergent policies but seek to avoid conflict--for example, in Korea, where we back opposing sides within the context of a shared interest in avoidance of war in the peninsula.

* Where we have different perceptions-- such as the Middle East and Africa--but where policies should at a minimum not obstruct efforts for peace.

* Relations with Europe and Japan, where on the whole American and Chinese interests run parallel.

Of the operational matters, the only issue requiring urgent attention is transfer of technology. Our restrictions on trade with Communist countries have as their purpose to prevent the strengthening of strategic capabilities hostile to us. But China is decidedly not a Soviet ally, nor is it in the same class of military power. China could not represent a military threat to American interests for the rest of this century, by which time current technology will be superseded. China, in my view, should be given the same status for technological transfer as India and Yugoslavia. It would convey that we understand, and take seriously, the strategic parallelism of interest.

n my experience, the best approach in discus sions with Chinese leaders is complete frank ness. It is wiser to admit that some positions are in a state of evolution than to pretend to settled views that dialogue will reveal as shallow or empty. It would help if--as the dialogue develops --the American positions could be given as much of a bipartisan cast as possible.

At the same time, Secretary Shultz's hosts must not place the entire weight of the trip on him. It is to be hoped that the Chinese contribution will transcend the occasional hectoring of recent years, especially the grating tendency to treat American presentations as if we were students taking an examination. Peking has to assume some responsibility of its own for the balance of power.

I am convinced that both sides to this dialogue will be represented by men with the wisdom to transcend the recent past. Neither side can have promoted the visit in order for it to fail; each side knows that a failure would not leave us with the status quo but mark a setback. Nor can one single exchange provide the necessary depth and stability. Senior Chinese leaders should continue the process in Washington. And however difficult the dialogue may be, negotiating with the Chinese has the advantage that undertakings will be strictly honored.

Many American leaders have visited Peking in the past decade. All have been impressed by their hosts' thoughtfulness and meticulousness. None will have gone at a more propitious juncture than Secretary Shultz. I have every confidence that his trip will mark a major step forward to the benefit of our two countries and the peace of the world.