In late December, Thailand and Cambodia reached another ceasefire agreement, their third since their long-running border conflict escalated in mid-2025. While decisions made in Phnom Penh and Bangkok are the most important factor in the agreement and its longevity, both the United States and China have competed to position themselves as peacemaker.
The US role – driven by Donald Trump’s ambition to mediate several international conflicts – has been relatively clear. Trump threatened higher tariffs on both trade-exposed Southeast Asian countries, helping to bring about the first ceasefire, signed in July. Trump has remained engaged since, attending the October signing of the Kuala Lumpur Peace Accords and speaking to the Thai and Cambodian prime ministers in December when fighting flared up again.
China’s role has been quieter, and throughout much of 2025, Beijing appeared cautious and uncertain about how to approach conflict between two of its close partners and neighbours in Southeast Asia. In July, Foreign Minister Wang Yi said China was ready to help mediate between the two parties. But, seemingly overshadowed by Trump’s loud approach, Beijing’s involvement in the subsequent ceasefire was limited to diplomatic participation at the ceremony, albeit on an equal footing with the United States.
Since a further round of fighting broke out in December, China has taken a more active role. Its envoy for Asian affairs, Deng Xijun, visited Bangkok and Phnom Penh, described by the Chinese foreign ministry as “shuttle diplomacy”. And in January, after Thailand and Cambodia reached a bilateral agreement, Wang Yi convened foreign ministers and defence officials from the three countries in Yunnan. Notably, and as pointed out publicly by a senior State Department official, this meeting occurred only after Thailand and Cambodia had already reached a ceasefire. China has also offered to provide 20 million yuan (around US$2.86 million) for rehabilitation of the damage to people and property, although this is much less than the $45 million of new programs announced by the United States.
China’s quiet approach is likely to pay off in the long term.
China has not sought to claim credit for any ceasefire or agreement – maybe because that would make it responsible. Rather, it has sought to position itself as a natural partner to both sides in protecting regional stability. An editorial in the China Daily described Beijing’s approach as “balanced and constructive” and in line with the “Asian way”, in contrast to the US transactional efforts. Predictably, China also references its efforts as supporting the “community of common destiny” with its neighbours. Indeed, important Chinese initiatives with mainland Southeast Asian countries, like the Lancang-Mekong Cooperation forum, or future connectivity projects, would face challenges if conflict between Thailand and Cambodia persists.
Given China’s overall influence in mainland Southeast Asia, this quiet approach to a serious conflict is perhaps surprising. It has deep ties with Bangkok and Phnom Penh, yet its role has been less prominent than its mediation between Iran and Saudi Arabia, a region where China’s influence is lower. One factor is likely risk-aversion: in a heated conflict, accusations of bias towards one side can escalate rapidly, especially given a strong international perception that China is closer to Cambodia than Thailand. Even Japan, which enjoys huge soft power in both countries, was heavily criticised for a misjudged intervention calling for the border to reopen.
China’s quiet approach is likely to pay off in the long term. By avoiding direct responsibility for any ceasefire yet positioning itself as a constructive partner that does not apply pressure, its diplomacy appears more attuned to Southeast Asian preferences than Trump’s pressure tactics, which at times appeared to irk Bangkok. And while Trump’s tariff threat clearly played a role earlier in 2025, the recent Thailand-Cambodia agreement did not prominently reference the Kuala Lumpur Peace Accords, which the United States continues to tout as Trump’s signature achievement. This subtle shift suggests a downplaying of the US role, which is likely to continue creating more space for China on this issue in 2026.
