As the curtain falls on 2023, the China-United States diplomatic relationship is about to greet its 45th anniversary in the new year. For all the optimism the November meeting of the two countries' leaders inspired, 2024 may still prove tricky for the lately volatile bilateral ties.

The Chinese Foreign Ministry's news briefing on Tuesday was illustrative of the less-than-optimistic atmosphere that has once again descended on China-US relations ahead of the upcoming new year.

The Chinese side has expressed strong dissatisfaction and resolute opposition, and made solemn representations with the US side over the latter's National Defense Authorization Act for 2024, said spokeswoman Mao Ning. The act, which US President Joe Biden signed into law on Dec 22 after it passed the review of Congress, interferes with Chinese domestic affairs, clamors for military support for Taiwan, and violates the one-China principle and the three joint communiques between the governments of the two countries, she said. "If the US side clings obstinately to its own course," she warned, "the Chinese side would take decisive, forceful measures to resolutely safeguard its own sovereignty security and development interests".

On the same occasion, the spokeswoman announced sanctions against a US company and two individuals for concocting and spreading "false narratives related to Xinjiang". The subjects of sanctions will be barred from entering China, or working with any Chinese entities, and any assets they have in the country have been frozen. The move, as Mao indicated, was in response to the US sanctioning two Chinese officials earlier this month, and is another step down the Xinjiang tit-for-tat path, highlighting relations continue to be fraught in the run-up to what should be a celebratory anniversary.

When the Chinese leader and his US counterpart met in San Francisco, the general anticipation was that they would manage to stabilize bilateral ties. The progress on fentanyl collaboration and high-level military dialogue was indeed conducive to stopping the worrisome downward spiral in ties. What has happened thereafter, however, shows the mutual distrust, if not outright animosity, between Beijing and Washington runs so deep that it is going to require a major booster to alter the downward trajectory of ties.

For 2024, a diplomatic thaw in its usual sense may be difficult to achieve. So, instead of pursuing the unachievable, Beijing and Washington should concentrate more on the true imperative of the San Francisco vision, demonstrate genuine realism, and work harder to stabilize the wayward relationship.

Like a person in his or her 40s, who in the Confucian ideal should be wise enough about affairs of the world, the soon 45-year-old China-US relationship, too, needs adult wisdom to stop it fraying.