Harry Harding, a renowned American scholar on Chinese studies, made a comment on China-US relations a few years ago, to the effect that the ties were still at a stage during which stability could only be attained by leaders' visits. It seemed to mean that the relations must be maintained through direct meeting between top leaders. Today, however, when we look at the situation again, we would probably draw a different conclusion: the ties have gone beyond the stage of relying on leaders' visits for stability.

The conclusion is based on the following facts.

First, more than 30 years after the relations normalized, the two sides have gradually developed a set of unspoken rules for cooperation in competition and co-existence in frictions, and, more importantly, set up scores of mechanisms for interaction and exchange in the fields of economy, trade, army and culture that had been propelled into a deeper stage by the historical unfolding of China-US strategic dialogue. Such interaction and exchange, both wide and profound, significantly reduced the possibility for a certain crisis to escalate into a full-scale confrontation, thus providing an "institutional guarantee" for stability in the relations.

Second, grasping the trend of our era, which is characterized by globalization, informalization and the rise of non-traditional security threats, the two countries have been working together to hammer out a new relationship mode between big countries that focuses on constructive cooperation. As a result, the two nations have deeply blended into each other in their economic, trade and security interests, and pushed the base of bilateral ties from a common threat stage into a common interest one. This is also shown in the repeated stress by American politicians lately that China should become a "responsible interest party" of the existing international system.

Besides, a series of new-type cooperation and diplomatic practices by the two countries in fighting against terrorism, nuclear proliferation and bird flu as well as in keeping regional stability have injected new "genes" into the stability of bilateral relations, with mutual benefit gradually becoming a policy goal deserving efforts of both nations.

Looking at President Hu's US tour from such an active perspective, people have reason to believe that this would be an important visit that can further enrich constructive cooperation, deepen cooperation and expand the base of bilateral ties. Compared with breakthroughs on some concrete issues, the achievement deserving even more expectation is to build a healthier political climate and more stable framework for the future development of China-US ties.

The general stability doesn't mean zero difference or even friction. On the contrary, various contradictions remained in economy, trade and security areas in recent days, whose delayed or inadequate handling would no doubt affect the stable situation in general. President Hu's US tour, during which he traveled from Seattle to Washington to Yale and talked about China-US economic and trade cooperation, China's peaceful development and the progress of Chinese civilization, will surely help the two strength trust, deepen understanding and enhance cooperation.

The Sino-US ties are displaying a certain kind of new historical trait. It is expected that this important meeting between top leaders would inject new vigor and vitality into long-term peace and stability of the relations.

By People's Daily Online; The author Yuan Peng is research fellow with the Institute of American Studies under China Institutes of Contemporary International Relations.