As tensions along the 817-kilometer border between Thailand and Cambodia continue to flare, the world’s diplomatic heavyweights are stepping up their efforts to pull the region back from the brink. In the days leading up to a crucial Association of Southeast Asian Nations (ASEAN) ministerial meeting in Kuala Lumpur, both China and the United States have launched parallel peace initiatives, hoping to halt the bloodiest clashes seen between the two neighbors in years.
The stakes are high—since hostilities reignited on December 8, 2025, roughly 60 people have lost their lives and more than 750,000 have been forced from their homes, according to reports compiled by Reuters and China Daily. The violence, which has stretched from the forested interior near Laos all the way to the coastal provinces, shattered a fragile truce that former U.S. President Donald Trump had helped broker back in July. That ceasefire, later expanded into a broader peace framework in October during talks in Malaysia, has proven unable to withstand the simmering distrust and territorial disputes that have long haunted the borderlands.
On Friday, December 19, U.S. Secretary of State Marco Rubio met with Thai Foreign Minister Sihasak Phuangketkeow, urging Bangkok to de-escalate and recommit to the ceasefire agreement. The U.S. State Department warned that further violence could fracture ASEAN unity and undermine the region’s stability. According to the department, Rubio “reiterated Washington’s support for a peaceful resolution” and pressed Thailand to show restraint.
Meanwhile, China has stepped out of the shadows to take a more assertive mediating role. On Thursday, December 18, Chinese Foreign Minister Wang Yi held separate phone calls with both Sihasak and his Cambodian counterpart, Prak Sokhonn. Beijing’s Foreign Ministry said both sides “expressed their desire to ease tensions and achieve a ceasefire.” Wang Yi emphasized, “The pressing priority is to make decisive moves to cease fire, minimize losses promptly and rebuild mutual trust,” as paraphrased by China Daily.
China’s involvement didn’t stop at phone diplomacy. The same day, Beijing dispatched Deng Xijun, its special envoy for Asian affairs, on a shuttle-diplomacy mission to both capitals in an effort to broker a ceasefire. According to Chinese Foreign Ministry spokesperson Lin Jian, both Thai and Cambodian envoys “highly appreciated China’s objective and impartial stance” and “welcomed the shuttle mediation by China’s special envoy and expressed hope that China would play an even more important role in de-escalating the situation and rebuilding peace.”
This marks a shift from China’s earlier, more subdued approach. For the first week of renewed fighting, Beijing kept a relatively low profile, perhaps waiting to see whether the U.S.-brokered peace would hold—or, as some observers suggest, to allow Trump’s intervention to be seen as failing before stepping in more forcefully. Whatever the motive, China’s recent moves have signaled its intent to be a central player in Southeast Asian security affairs, particularly as the region’s stability comes under threat.
Despite these diplomatic overtures, the situation on the ground remains volatile. On December 19, the Thai Defence Ministry reported that Cambodian forces fired heavy weapons across the border, prompting retaliatory strikes by Thailand. Bangkok has accused Phnom Penh of laying new landmines—one of which maimed a Thai soldier in November—while Cambodia insists its actions are purely defensive. The mutual recriminations have only deepened the distrust that has plagued attempts at peace.
Thailand has made clear that any path to peace must begin with an immediate halt to Cambodian offensives and a framework for a verifiable ceasefire. For its part, Cambodia maintains it is responding to Thai military aggression. The rhetoric on both sides remains heated: a Thai general was quoted as saying the goal is “to render Cambodia militarily ineffective for a long time,” while Thai Prime Minister Anutin Charnvirakul recently spurned international mediation, stating his government “stands firm with our determination to preserve, protect, and defend integrity of our land and our people at all cost.”
As the violence continues, the human cost grows. The number of displaced people has now surpassed half a million, with some estimates as high as 750,000. Makeshift camps have sprung up on both sides of the border, and aid agencies warn of an unfolding humanitarian crisis if the fighting isn’t brought to an end soon.
The upcoming ASEAN ministerial meeting in Kuala Lumpur, scheduled for December 22, is now viewed as a make-or-break moment. It will mark the first direct talks between the Thai and Cambodian foreign ministers since the latest round of fighting erupted. Malaysian Prime Minister Anwar Ibrahim, who chairs ASEAN and played a key role in brokering the earlier ceasefire, struck a cautiously hopeful tone this week. “The commitment shown by both prime ministers gives us hope that this meeting will produce tangible progress,” Anwar told reporters, though he acknowledged the many setbacks that have dogged previous peace efforts.
Both Thailand and Cambodia have confirmed their intention to attend the talks, but as of December 19, Cambodia had not made any public statements regarding the latest diplomatic outreach. Thailand’s Foreign Ministry, for its part, described recent conversations with China as “frank and constructive,” and said both sides had agreed to maintain close dialogue to safeguard regional peace and stability. Still, the absence of a clear commitment to a ceasefire in official Thai statements leaves many observers wary.
Much of the region—and indeed the world—is now watching to see whether this new round of diplomacy can succeed where past efforts have faltered. The July ceasefire and the October peace declaration, both brokered under significant outside pressure, ultimately failed to address the deep-seated mistrust between the two governments. As one analyst told China Daily, “The peace declaration signed in Kuala Lumpur was ultimately a product of outside pressure and belied the continuing low levels of trust between the two governments.”
With the ASEAN meeting looming and the humanitarian crisis worsening by the day, the pressure is on for regional leaders and international mediators to find common ground. Whether China’s more active involvement will tip the balance remains to be seen. For now, the border remains a flashpoint—and the world waits to see if diplomacy can prevail over the drumbeat of war.
