A New Chapter in Southeast Asian Diplomacy
For months, China appeared content to let the United States take the lead in addressing the border conflict between Cambodia and Thailand. Beijing repeatedly emphasized that it had “its own way” of handling regional disputes, suggesting a preference for quiet diplomacy behind the scenes. But in late December, that approach shifted dramatically. Chinese Foreign Minister Wang Yi hosted his Cambodian and Thai counterparts for trilateral talks in Yunnan province, signaling Beijing’s readiness to step into the spotlight and claim credit as peacemaker. The meeting came just days after a new ceasefire was brokered, and China used the occasion to assert that its steadier, lower-key diplomatic approach was superior to Washington’s more confrontational tactics.
The conflict between Cambodia and Thailand has flared repeatedly along their 800-kilometer (500-mile) shared border, with roots in colonial-era demarcation disputes and competing claims to territory surrounding ancient temple sites. The most recent escalation began in May with the killing of a Cambodian soldier, leading to intense fighting in July that left dozens dead and displaced hundreds of thousands of civilians. A brief ceasefire brokered by Malaysia with US support in October collapsed in December after renewed clashes, including Thai airstrikes into Cambodian territory.
The human toll has been substantial. According to various reports, at least 101 people have been killed in the latest rounds of fighting, with more than half a million civilians displaced from their homes in both countries. Villages along the border lie deserted, many littered with shrapnel and unexploded ordnance. The economic impact has also been severe, with border closures disrupting regional supply chains and threatening Chinese-funded infrastructure projects that connect Kunming to Bangkok and feed industrial zones on Cambodia’s coast.
Against this backdrop, China’s decision to host high-level peace talks in Yunnan represents a significant diplomatic maneuver. Beijing has multiple strong interests in brokering a lasting ceasefire, not least protecting its extensive strategic investments and economic corridors in both countries. But the intervention also signals China’s growing appetite to vie for influence in Southeast Asia and beyond, challenging traditional US dominance in regional security matters.
Competing Diplomatic Philosophies
The contrast between US and Chinese approaches to mediation has been striking. The Trump administration adopted a high-pressure strategy, threatening punitive tariffs on both Cambodia and Thailand as part of ongoing trade negotiations. President Trump reportedly warned both nations that no further tariff discussions with the United States would proceed if fighting persisted, leveraging America’s economic might to force compliance.
“We appreciated the efforts of the US… But sometimes, you know, we cannot always operate on a fixed timeframe,” Thai Foreign Minister Sihasak Phuangketkeow told reporters in December, alluding to the bruising tactics employed by Washington. The Trump administration had sought a joint declaration dubbed the “Kuala Lumpur Peace Accords” ready for signing during an ASEAN summit in Malaysia, but the rushed process proved unsustainable.
China, by contrast, has positioned itself as a patient mediator that respects regional sovereignty and processes. “China’s efforts to promote peace and dialogue never impose on others or overstep its bounds,” Wang Yi told his Thai counterpart during a separate bilateral meeting in Yunnan. The state-run Global Times newspaper was even more direct in its criticism of Western approaches.
“Unlike many past mediations dominated by the West, China does not adopt a condescending approach, impose political conditions or seek geopolitical advantages,”
the nationalist tabloid declared in a December 29 editorial, barely disguising its criticism of Washington’s tactics.
Associate Professor Ma Bo of Nanjing University explained the fundamental difference between the two approaches. “US mediation tends to prioritise speed and leverage to stop fighting quickly, often through visible pressure,” he told The Straits Times. “China’s approach places greater emphasis on process, dialogue and post-crisis stabilisation, with the aim of preventing a rapid relapse into confrontation. In practice, China’s approach is more focused on sustaining calm after the ceasefire.”
This philosophical divide reflects broader differences in how Washington and Beijing view their roles in the world. The United States often employs coercive diplomacy as a tool of first resort, using its economic and military leverage to achieve quick results. China, while certainly not above using its economic power strategically, prefers a subtler approach that emphasizes long-term relationship building and what Beijing calls “win-win” solutions.
The Limits of Coercive Diplomacy
The Trump administration’s approach initially appeared successful when Cambodia and Thailand agreed to an unconditional ceasefire on July 28 after five days of fighting. However, with hindsight, many analysts now view that agreement as superficial. It papered over fundamental differences that neither side was ready to compromise on, setting the stage for renewed violence when those unresolved grievances resurfaced.
Thailand suspended the US-brokered peace deal in November after accusing Cambodia of laying new landmines that maimed 11 Thai soldiers. Fighting reignited in December with both sides trading accusations about who fired first, culminating in Thai air strikes into Cambodian territory on December 8. A fresh ceasefire was finally agreed on December 27, but not before additional lives were lost and more civilians were forced to flee their homes.
The failure of the July ceasefire demonstrated the limits of Washington’s pressure-based approach. While economic threats can produce short-term compliance, they rarely address the underlying causes of conflict or build the trust necessary for sustainable peace. China’s emphasis on gradual confidence-building and addressing root causes may prove more effective over time, though it also carries the risk of prolonged instability in the interim.
China’s Strategic Calculus
China’s decision to step forward as a mediator is driven by multiple strategic considerations. Foremost among these is the protection of Beijing’s extensive economic interests in both countries. China has long promoted economic and infrastructure development in the Mekong subregion through its Belt and Road Initiative. The ongoing conflict presents a significant challenge to connectivity between China and mainland Southeast Asia along corridors that link Kunming to Bangkok and feed Chinese-funded industrial zones on Cambodia’s coast.
Protracted fighting jeopardizes both physical infrastructure and investor confidence. The border closure has already disrupted segments of regional supply chains and economic activities, impacts further aggravated by the ongoing crisis in neighboring Myanmar. For Beijing, stabilizing the region is essential to protecting its investments and ensuring the continued viability of its economic projects.
Beyond immediate economic concerns, China sees this mediation effort as an opportunity to enhance its international stature and further entrench its influence in Southeast Asia. By taking the lead on conflict resolution, Beijing seeks to preempt other powers, especially the United States, Japan, and India, whose Indo-Pacific visions compete with China’s own. A successful mediation would reinforce the narrative that China, not Washington, is the indispensable security manager of mainland Southeast Asia.
Against the backdrop of negative perceptions stemming from China’s actions in the South China Sea, a constructive role in mainland Southeast Asia could help soften its image. This role also supports Beijing’s claim to be a responsible power and aligns with President Xi Jinping’s Global Security Initiative, which calls for a new approach to security based on dialogue rather than confrontation.
Beijing’s backing also carries political weight in both capitals. Cambodia has demonstrated strategic dependence on China in recent decades, with Beijing playing a central role in modernizing Cambodia’s defense sector. This includes financial and infrastructure support for the renovation of the Ream Naval Base, as well as extensive military cooperation through joint drills, aid, and equipment transfers.
In Thailand, China’s economic footprint is equally significant. China plays an important role in Thailand’s trade, tourism, infrastructure investment, and collaboration in green and digital economies. Although Thailand remains a military ally of the United States and holds the status of a Major Non-NATO Ally, its relationship with Washington has experienced periodic strain. These dynamics have created space for Beijing to deepen its ties with Bangkok, particularly during periods when Thailand’s relations with the West are tense.
The Wider Regional Context
China’s intervention in the Cambodia-Thailand conflict does not occur in isolation. Beijing is already contending with a civil war in Myanmar, persistent tensions in the South China Sea, and its own domestic economic challenges. Preventing further regional instability in its periphery is therefore a key priority for Chinese policymakers.
The mediation effort also builds on China’s growing experience as a peacemaker. In 2023, Beijing helped broker the surprise rapprochement between Iran and Saudi Arabia, ending a seven-year rift between the two Middle Eastern powers. That success demonstrated China’s ability to leverage its relationships with multiple parties to facilitate dialogue, even in deeply intractable conflicts. Applying those lessons to Southeast Asia represents a natural extension of China’s diplomatic ambitions.
However, Beijing faces significant obstacles in translating its peacemaker ambitions into meaningful action in Southeast Asia. Thai media has reported suspicions that China’s support for Cambodia, including the Golden Dragon joint military exercise at the end of May, may have emboldened Phnom Penh’s most recent border claims. Some Thai commentators have even suggested that China supplied weapons to Cambodia, enabling the recent attacks on Thailand.
Nor has Beijing’s offer of mediation been universally welcomed. While Thai leaders have politely acknowledged international offers to help de-escalate the conflict, they initially favored bilateral talks before accepting mediation from Malaysia as ASEAN chair. Memories of contentious international arbitration, particularly the International Court of Justice rulings on border disputes with Cambodia in 1962 and 2013, have fostered deep public skepticism in Thailand toward external mediation.
China’s moves may also have sent the wrong signal to ASEAN, where Malaysia ultimately played a decisive role in brokering the July ceasefire. ASEAN efforts can collide with China’s attempt to assert its own stronger role, even as Beijing proclaims support for “regional solutions.” Overly assertive Chinese diplomacy risks triggering backlash from both disputing parties and other ASEAN members wary of Beijing’s growing influence.
The Fragile Path Forward
The trilateral meeting in Yunnan secured agreement on a five-part roadmap to lock in the ceasefire and stabilize ties. The priorities include consolidating the ceasefire, with China helping with landmine removal operations and providing support to the ASEAN Observer Team monitoring the ceasefire. Both countries also agreed to resume exchanges and rebuild political trust, with Beijing pledging involvement at every stage.
“An important consensus was reached,” Wang Yi said after the meeting, according to a Foreign Ministry statement. The diplomatic and military authorities of both countries engaged in face-to-face, in-depth exchanges, demonstrating what Beijing described as a “positive and open attitude.” Both sides expressed commitment to easing tensions and improving bilateral relations on the basis of the ceasefire.
Chinese officials emphasized three key principles emerging from the talks: looking forward and moving ahead together, proceeding step by step without stopping, and rebuilding mutual trust. The third point was deemed particularly important, given that the conflict had led to a significant loss of trust between the two neighbors.
“The gathering by the Fuxian Lake is intended to heal the wounds caused by the conflict, dispel the estrangement between the two sides, and truly restore friendly relations,” Wang Yi stated. “This serves the interests of the Cambodian and Thai peoples and is the shared expectation of all parties.”
Despite the positive rhetoric from the diplomatic talks, the situation on the ground remains precarious. Just hours after the Yunnan summit concluded, Thailand’s army accused Cambodia of flying more than 250 drones over Thai border areas on the night of December 28. The Thai military characterized this as a violation of the ceasefire agreement and warned that it might reconsider the release of 18 Cambodian soldiers held captive since July.
Cambodia’s Defense Ministry rejected the allegations, with Foreign Minister Prak Sokhonn describing the drone sightings as “a small issue” that both sides had agreed to investigate and resolve immediately. The Cambodian side reported that calm prevailed along the border since the ceasefire took effect, highlighting the differing interpretations of events that continue to plague the relationship.
The drone incident illustrates the fundamental challenge facing any peace process: deep-seated mistrust between the two sides. Years of conflict, nationalist posturing, and competing historical narratives have created profound mutual suspicion that cannot be erased by diplomatic declarations alone. Building genuine confidence will require sustained effort and tangible progress on the ground.
The Complex Roots of Conflict
The Cambodia-Thailand border dispute has deep historical roots that complicate any resolution effort. The two countries share an 800-kilometer border that was drawn by colonial powers without regard to local ethnic and economic realities. Both nations claim territory surrounding the 11th-century Preah Vihear Temple, a UNESCO World Heritage site that has been a flashpoint for violence in the past.
Beyond the territorial dispute, the conflict has been exacerbated by other factors. Transnational crime, particularly scam compounds and human trafficking operations that flourished during the COVID-19 pandemic, has become a major point of contention. Thailand launched a cross-border crackdown on these operations in February, which some analysts believe contributed to the escalation of tensions.
The October 26 Joint Declaration brokered by Malaysian Prime Minister Anwar Ibrahim listed the removal of scam compounds as the sixth of eight steps required before joint management of the border could be re-established. The most recent December 27 agreement ranked the suppression of such crimes at tenth place in its 16-point plan, suggesting that even the priority assigned to this issue remains unclear.
According to monitoring groups, there are 274 scam compounds currently operating in Cambodia, representing an illegal industry worth tens of billions of dollars annually. The issue gained international attention in October when the United States seized $15 billion in assets from Prince Group and indicted its Chinese-Cambodian chairman for operating forced labor scams. Additional sanctions and arrest warrants have been issued by multiple countries, including Thailand, which has issued warrants for three Cambodian senators and their family members.
Addressing this criminal element will be essential for any lasting peace, but it also presents challenges. Crackdowns on lucrative illegal operations can provoke resistance from powerful interests within both countries, potentially undermining the very stability that peacekeepers seek to establish.
A Geopolitical Chessboard
The Cambodia-Thailand conflict has become a proxy for broader competition between the United States and China for influence in Southeast Asia. Both powers have been actively involved in mediation efforts, each advancing its own approach to conflict resolution and regional security.
President Trump has been characteristically boastful about America’s role, declaring himself “the President of PEACE” and claiming to have “saved thousands of lives” through his intervention. “I am pleased to announce that, after the involvement of President Donald J. Trump, both Countries have reached a CEASEFIRE and PEACE,” he posted on social media after the December agreement. He added that he had instructed his trade team to restart negotiations with both countries.
China has taken a more measured public posture, emphasizing its support for regional processes and its commitment to impartial mediation. “China is deeply saddened by the casualties inflicted on both sides and expresses heartfelt sympathies,” a Foreign Ministry statement said. “China will maintain its fair and impartial position and continue having close communication with both sides, actively facilitate talks for peace and play a constructive role for a ceasefire.”
The contrast is telling. The United States wants quick fixes and leverage; China prefers slow influence and presence. Both great powers seek to shape the regional order, and both were watching closely as Malaysia facilitated earlier talks. For ASEAN, this creates both opportunities and challenges.
On one hand, the involvement of external powers provides additional resources and attention to regional conflicts. On the other, it risks turning Southeast Asia into a theater for great power competition rather than a platform for internal solidarity. Malaysia’s diplomatic choreography demonstrated that ASEAN can still act meaningfully when conflict erupts, but the bloc’s vaunted principle of “noninterference” is increasingly untenable in the face of humanitarian crises and militarized nationalism.
Sean O’Neill, the US nominee for ambassador to Thailand, reinforced President Trump’s message, emphasizing that the conflict would not serve the interests of the Thai-US alliance. As a reward to Cambodia, Malaysia, and Thailand for accommodating President Trump’s demands, the United States reduced the reciprocal tariffs imposed on these three countries from 36 percent to 19 percent.
The Question of Neutrality
Despite Beijing’s claims of impartiality, questions persist about China’s ability to serve as a neutral mediator given its close relationship with Cambodia. Thailand has historically maintained a more balanced approach to great power relations, hedging between China and the United States, while Cambodia has aligned itself much more closely with Beijing in recent years.
Thai commentators have noted that China’s reiteration of support for Cambodia during the crisis, along with the Golden Dragon joint military exercise at the end of May, may have bolstered Phnom Penh’s confidence in its defense posture. Some have even suggested that China supplied weapons to Cambodia, enabling the recent attacks on Thailand. These perceptions, whether accurate or not, complicate Beijing’s claim to neutrality.
Mr. Virak Ou, political analyst and founder of the Future Forum think-tank in Phnom Penh, suggested that China’s decision to intervene more forcefully was made easier by Thailand’s military superiority. “Certainly, I think the facts on the ground are likely the main factors for the ceasefire, but perhaps China’s involvement could ensure a lasting ceasefire,” he said. “The China factor could just be an off-ramp for both countries to settle on a ceasefire, which Cambodia wants, and Thailand is probably happy now with the outcome on the ground.”
Mr. Lye Liang Fook, a China expert at the ISEAS-Yusof Ishak Institute, noted that by stepping in as a peacemaker, China allowed both sides a face-saving way to explain to domestic audiences why they are de-escalating. “Cambodia, in particular, would welcome a dignified exit, given its weaker military position,” he observed.
Whether China can maintain the perception of neutrality while also advancing its strategic interests remains to be seen. Beijing’s commitment to non-interference in internal affairs is a cornerstone of its foreign policy, but its actions in the region sometimes tell a different story. In Myanmar, for example, China’s engagement with the junta has been seen as self-serving and disproportionately aligned with authoritarian actors, despite Beijing’s professed desire to broker peace.
The Regional Response
Regional actors have welcomed China’s increased involvement in the peace process, viewing it as a complement to rather than a replacement for other diplomatic efforts. Malaysia, as ASEAN chair, played a crucial role in brokering the initial ceasefire in July and has maintained its engagement despite China’s higher-profile intervention.
The United Nations has also welcomed the ceasefire agreement, with Secretary-General Antonio Guterres describing it as “a positive step toward alleviating the suffering of civilians, ending current hostilities, and creating an environment conducive to achieving lasting peace.” The international community broadly shares this assessment, though many observers remain cautious about the durability of the truce.
China has pledged practical support beyond diplomatic mediation, including assistance with ceasefire monitoring, humanitarian aid, and demining cooperation. The first batch of Chinese humanitarian aid, including food, tents, and blankets, arrived in Cambodia on December 29, according to Wang Wenbin, China’s Ambassador to Cambodia.
Thailand has indicated that it wants China to play more than a mediator role. “Thailand… wants China to play a constructive role in ensuring a sustainable ceasefire by sending such signals to Cambodia [against reviving the conflict],” Foreign Minister Sihasak Phuangketkeow stated. This suggests that Bangkok sees Beijing as having particular leverage over Phnom Penh that could help ensure compliance with the agreement.
The military dimension of the conflict has received particular attention, with the armed forces of all three countries scheduled to join talks in Yunnan to discuss ways to consolidate the ceasefire, resume exchanges, and build political trust. Including military representatives in the dialogue process is seen as essential for addressing the technical aspects of disengagement and creating mechanisms to prevent accidental escalation.
As part of the December 27 agreement, Thailand pledged to return 18 Cambodian soldiers held as prisoners since July, fulfilling a major demand from the Cambodian side. The release was contingent on the ceasefire being fully maintained for 72 hours, a condition that appeared to have been met despite the drone incident that briefly threatened to derail the process.
The broader diplomatic community has also weighed in, with Australia, Japan, the United Kingdom, Germany, and France joining China and the United States in welcoming the ceasefire. This international consensus provides additional pressure on both parties to comply with the agreement, but it also underscores the global attention focused on this previously local conflict.
Assessing China’s Peacemaker Ambitions
The Cambodia-Thailand mediation represents an important test of China’s evolving security role in Southeast Asia. Beijing has long sought to position itself as a responsible great power that contributes to regional stability, but its actions in the South China Sea and elsewhere have often undermined this narrative. A successful mediation in mainland Southeast Asia could help repair that image and demonstrate China’s constructive potential.
However, significant obstacles remain. Thai skepticism toward external mediation runs deep, rooted in historical experiences with international arbitration that Bangkok viewed as unfavorable. Cambodia’s preference for international legal processes, meanwhile, reflects its desire to internationalize what it sees as an unequal contest with its larger neighbor. These divergent instincts complicate any third-party mediation effort.
China must also navigate the complex dynamics of ASEAN centrality. The regional bloc values its role as the primary forum for addressing regional disputes and views external intervention with suspicion, even when that intervention comes from a fellow Asian nation. Beijing has often been criticized for its “Janus-faced” approach to ASEAN, publicly affirming its support for ASEAN centrality while simultaneously pursuing bilateral arrangements that undermine it.
If the conflict escalates anew despite the latest ceasefire agreement, Washington could step in to assert its influence and push for a resolution. President Trump has already demonstrated his willingness to engage directly, holding phone conversations with the leaders of both Thailand and Cambodia and warning that no further tariff negotiations would proceed if the fighting persisted.
China’s continued engagement, reflected in the recent talks held in Yunnan, signals a deliberate effort to shape outcomes in an informal and low-profile manner. This strategy underscores Beijing’s determination to assert its regional role while sidestepping direct confrontation with the United States. But it also risks leaving China caught between its desire for influence and its commitment to non-interference if the situation deteriorates.
Looking ahead, several factors will determine whether China can successfully translate its peacemaker ambitions into reality. Building trust with Thailand will be essential, particularly through government and military channels that reassure Bangkok of Beijing’s commitment to impartiality. Supporting ASEAN-led mechanisms for future mediation and trust-building could also help alleviate suspicions of power projection or dominance.
At the international level, China could propose that the UN recommend the establishment of a regional fact-finding body to promote a shared understanding of the conflict. Such efforts would need to be grounded in ASEAN’s dispute settlement mechanisms, allowing Beijing to demonstrate its commitment to and promotion of ASEAN centrality while still playing a leading role.
The stakes extend beyond the immediate conflict. How China handles this mediation will signal to other Southeast Asian nations whether Beijing can be trusted as an honest broker or whether its interventions will always be self-serving. It will also test whether China’s approach to conflict resolution, which emphasizes gradual confidence-building over quick fixes, can produce results in a region accustomed to more immediate forms of crisis management.
The Bottom Line
The Cambodia-Thailand border conflict has evolved from a local dispute into a geopolitical contest between competing models of international engagement. China’s emergence from the diplomatic shadows to claim credit for mediating the latest ceasefire represents a significant development in Southeast Asian security dynamics, with implications that extend far beyond the immediate region.
- The border conflict between Cambodia and Thailand has killed at least 101 people and displaced more than half a million civilians in recent rounds of fighting.
- China hosted trilateral talks in Yunnan province in late December, presenting its diplomatic approach as superior to Washington’s pressure-based tactics.
- Beijing has strategic interests in brokering peace, including protecting Belt and Road Initiative infrastructure and expanding influence in Southeast Asia.
- The United States initially brokered a July ceasefire using tariff threats, but that agreement collapsed in November amid renewed violence.
- The latest five-point roadmap includes consolidating the ceasefire, landmine removal operations, and rebuilding political trust.
- Thailand has accused Cambodia of violating the new ceasefire with drone flights, highlighting the fragility of the truce.
- Transnational crime, particularly scam compounds and human trafficking, remains a complicating factor in the border dispute.
- China’s mediation effort builds on its previous success brokering the 2023 Iran-Saudi Arabia rapprochement.
- ASEAN, led by Malaysia as chair, has played a crucial role in earlier mediation efforts and continues to be engaged.
- The situation remains volatile, with deep-seated mistrust between the parties and unresolved territorial disputes threatening lasting peace.
