The start of a new year always generates fresh hopes and expectations, and this year is no exception. The leaders of China and the United States have fueled the seasonal sense of anticipation by raising hopes that the tensions between the two countries will be eased.

On Tuesday, President Xi Jinping and his US counterpart Donald Trump exchanged congratulatory messages on the 40th anniversary of the forging of diplomatic ties between the two countries, vowing to push for more cooperation and the further progress of bilateral relations.

This came just two days after the two leaders had a telephone conversation in which they expressed their shared willingness for an agreement to be reached in the two sides' trade talks. The working teams of the two countries are actively promoting the implementation of the consensus reached between the two leaders in Argentina last month.

Despite the vicissitudes over the years, bilateral relations have withstood all the twists and turns. And in doing so, the two sides have learned from experience that cooperation, rather than confrontation and estrangement, should be the defining theme for their relations.

Admittedly, bilateral relations have met a strong headwind since the Donald Trump administration — manifesting the anxieties of many in the US at a changing world over which the country seemed to be losing the grip — unilaterally launched a trade war with China and stubbornly provoked it over sensitive issues such as the South China Sea. But experience has repeatedly shown that the two countries benefit from conducting reciprocal cooperation, and both lose if the atmosphere between them turns cold.

As long as both sides bear in mind the larger picture of bilateral ties and opt for dialogue and negotiations to resolve their differences, there is no reason why their relations cannot continue the general trend of increasing engagement that has benefited both countries over the past 40 years.

And at a time when the world is undergoing profound changes and facing rising challenges and uncertainties, a rapport between Washington and Beijing would also be a welcome signal that they recognize that no country can be an island unto itself in today's interconnected world, in which all actions may prove to have the storm-inducing wings of butterflies.

It is to be hoped the two sides can now demonstrate the political wisdom that will enable them to deliver on the welcome sense of optimism that prevails as we enter 2019.