Thailand-Cambodia conflict: the United States and China try to calm the game

China and the United States have taken nearly simultaneous diplomatic measures to help ease tensions between Thailand and Cambodia.

Clashes continue along the border, and Thai military operations are currently extending beyond the immediate border.

See: Thailand-Cambodia Conflict: Army says it is targeting cybercriminals and casinos

Both countries are seeking to position themselves as mediators to contribute to the restoration of regional stability.

Bangkok rejects any external pressure for a ceasefire

Local security forces control the fire of a house hit by a Cambodian rocket in Kantharalak district, Si Sa Ket province, on December 14, where a Thai was killed by shrapnel. Photo: Royal Thai Army

The Foreign Minister, Sihasak Phuangketkeow, rejected suggestions that Washington had pressured Thailand into accepting a ceasefire, stressing that any cessation of hostilities had to be initiated by Cambodia.

He also stated that Thailand had never promised China to end its military operations, maintaining its long-standing position on the conditions required for a ceasefire.

Washington says it is concerned about a prolonged escalation

A building burns after a Cambodian BM-21 rocket attack in Kantaralak district, Si Sa Ket province, on Saturday, December 13, 2025. Four civilians were seriously injured by shrapnel. Photo: Royal Thai Army

During a recent telephone conversation with US Secretary of State Marco Rubio, Mr. Sihasak indicated that the exchange had been motivated by international concerns about an escalation of fighting along the border between Thailand and Cambodia.

According to him, the United States sought to better understand the situation on the ground, to explore the prospects for de-escalation and to express their willingness to provide assistance.

A ceasefire is impossible without concrete guarantees

On December 9 at 6:10 pm, the HTMS Thepa of the Royal Thai Navy conducted naval artillery fire from the Gulf of Thailand to support the Marines in destroying Cambodian military targets and reclaiming the Ban Sam Lang area in Trat Province.

Thailand has made it clear that it is ready to reduce tensions, he said, but a ceasefire cannot be implemented unilaterally.

Cambodia should first demonstrate its sincerity by ceasing hostilities before talks can continue.

Clear mechanisms would also be needed, including agreed measures on how a ceasefire would be implemented and verified.

These technical details, he said, should be discussed directly by the military authorities of the two parties.

« A ceasefire cannot be based on intentions or announcements », said Mr. Sihasak.

« It requires detailed discussions on its implementation, format and supervision to ensure compliance. »

He reaffirmed that Mr. Rubio had not exerted pressure on Thailand during the call, but had simply shared his concerns.

In fact, he said, the American side spoke very little and mainly listened to Thailand's explanations.

Thailand has made it clear that, although it is seeking to reduce violence, it cannot do so alone, he said, adding that any ceasefire proposal must come directly from Cambodia, and not from a third country.

According to Mr. Sihasak, Mr. Rubio welcomed Thailand's position.

He added that the issue of the border between Thailand and Cambodia could be discussed in more detail at a special meeting of ASEAN Foreign Ministers in Kuala Lumpur on Monday.

Beijing affirms a willingness to ease tensions, without formal commitment

A Thai F-16 fighter jet bombed and destroyed a casino in the Chong An Ma district after the Thai army discovered that the establishment was serving as a base for the Cambodian army and a hideout for heavy weapons. Photo: Thai Armed Forces

Responding to the remarks of Chinese Foreign Minister Wang Yi, who said he had raised the issue with Thailand, Mr. Sihasak returned to Bangkok's position.

He specified that Thailand had made no commitment to ease tensions or to implement a ceasefire.

He stated that Thailand had only expressed its willingness to ease tensions and its desire to avoid a prolonged conflict.

Any ceasefire must be proposed by Cambodia and accompanied by concrete measures demonstrating a sincere intention.

Sino-US mediation on regional geopolitical stakes

Image illustrating China's and the US influence on the world. Source: The Nation Thailand

Associate Professor Somjai Phagaphasvivat, a political economist, said that China and the US are both seeking to position themselves as mediators to ease tensions between Thailand and Cambodia.

In the case of the US, he said, this approach has been explicitly stated as part of their general policy, with Washington stating its intention to influence global outcomes, particularly on issues of peace and security.

China, meanwhile, is already benefiting from certain advantages, having expanded its influence in recent years through trade and having established strong relations with countries in the region, he said.

See also:

Traveling to Thailand despite the conflict with Cambodia: what you need to know

Thailand-Cambodia conflict: Bangkok 'disappointed' by Trump's statements

Thailand–Cambodia: fighting continues, no ceasefire

Thailand-Cambodia: ceasefire collapses, fighting resumes

Mines: Thailand unveils new damning evidence against Cambodia

Source: Bangkok Post