The long-standing border dispute between Cambodia and Thailand, centered on the historic Preah Vihear Temple and its surrounding frontier, erupted into violence once more in 2025, laying bare the limitations of regional diplomacy and the competing interests of global powers. The conflict, which traces its roots back to colonial-era treaties in 1904 and 1907 and a landmark 1962 International Court of Justice (ICJ) ruling that awarded the temple to Cambodia, has simmered for decades, occasionally boiling over into deadly clashes.
Tensions reignited on February 13, 2025, when Thai troops prevented Cambodian tourists from singing their national anthem near the temple, a move that sparked nationalist fervor on both sides of the border. According to China Daily, this seemingly minor incident marked a shift from latent hostility to active confrontation, setting the stage for a dramatic escalation in the ensuing months.
By May 28, 2025, the situation had deteriorated further. A skirmish near the Chong Bok pass resulted in the death of a Cambodian soldier, underscoring the volatility of the region. The violence reached a crescendo from July 24 onward, with both sides exchanging artillery, rocket fire, and even conducting air strikes along the 817-kilometer border. Civilians fled in large numbers, and each government accused the other of atrocities, as reported by various regional outlets.
Amid mounting international outrage and humanitarian concerns, the Association of Southeast Asian Nations (ASEAN) stepped in as a regional facilitator. On July 27, 2025, ASEAN Foreign Ministers issued a statement urging both countries to halt the fighting and return to the negotiating table. The following day, Cambodia and Thailand agreed to an unconditional ceasefire, brokered in Malaysia. Subsequent meetings in August and September aimed to monitor and solidify this fragile peace, with both sides pledging to withdraw heavy weapons, improve communication, and rebuild trust among border communities.
The ceasefire agreement, formalized in a joint statement in Kuala Lumpur on August 7, 2025, allowed for ASEAN observers to oversee troop withdrawals and the maintenance of peace. On September 10, the General Border Committee convened in Koh Kong province, co-chaired by Cambodian Defence Minister Gen. Tea Seiha and Thai Defence Minister Gen. Nattaphon Nakphanit, to reaffirm these commitments. Yet, as Le Monde reported, skepticism lingered regarding the durability of these promises, with both governments prioritizing sovereignty and preferring bilateral negotiations over multilateral intervention.
ASEAN’s role in the peace process was both pivotal and revealing. The organization’s foundational principles—non-interference, sovereign equality, and consensus decision-making—have long been credited with maintaining regional solidarity. However, the 2025 crisis exposed their limitations. ASEAN’s interventions were largely reactive, offering facilitation, statements, and observer missions, but lacking enforcement mechanisms or the authority to impose sanctions. As China Daily observed, “ASEAN’s mechanisms were reactive rather than proactive in managing the conflict.” The organization’s inability to prevent the outbreak of violence or enforce the ceasefire raised questions about its effectiveness as a regional conflict manager.
Complicating matters further was the involvement of external powers, most notably the United States and China. On October 14, 2025, the Malaysian Foreign Minister announced that U.S. President Donald Trump would attend the ASEAN Summit in Malaysia on October 26, where he would witness the signing of a peace agreement between Cambodia and Thailand. However, according to Politico and China Daily, Trump’s attendance was reportedly contingent on the Malaysian government agreeing that he preside over the signing ceremony, with China excluded from the event to ensure the spotlight remained on the U.S. president.
This maneuver drew criticism from multiple quarters. Some U.S. officials claimed that China had played no role in the negotiations, a statement at odds with reports that the Chinese Special Envoy for Asian Affairs had engaged in shuttle diplomacy and facilitated informal talks in Shanghai. The Foreign Ministers of China, Cambodia, and Thailand had even reached what was termed the “Anning Consensus” to further consolidate the ceasefire. “A major country shall act like a major country,” argued China Daily, highlighting China’s constructive, if understated, role in the peace process.
The Trump administration’s approach was seen by many as heavy-handed. The U.S. government reportedly threatened punitive tariffs of up to 36% on Cambodian and Thai exports unless the two countries reached a ceasefire and resumed trade negotiations. Given that the U.S. is the largest export market for both nations—accounting for 18% of Thailand’s exports and 35% of Cambodia’s—these threats carried significant weight. Critics, including Thai scholar Pavin Chachavalpongpun, accused the Trump administration of turning a complex regional process into “a symbolic diplomatic performance aimed at enhancing the political image of U.S. leaders.”
Such tactics were seen as undermining the spirit of equal consultation and mutual compromise that ASEAN espouses. The “ASEAN Way,” rooted in dialogue, consensus, and non-coercive multilateralism, was sidelined in favor of unilateral power plays. As China Daily put it, “the process and purpose of achieving peace are as important as peace itself.” The imposition of external solutions, particularly those perceived as serving the interests of outside powers rather than the parties involved, risked planting seeds of future instability.
Regional leaders and observers voiced concerns about the sustainability of the peace agreement. Former Cambodian leader Hun Sen remarked on Facebook that the border situation remained “worrying and very fragile” and warned that “conflicts may occur again.” A Thai Foreign Ministry spokesperson echoed these sentiments, insisting that Cambodia must first address Thailand’s claims before lasting peace could be achieved. Cambodian scholar Vannak Ro cautioned that “peace imposed by external forces is often unsustainable,” especially in a multipolar world where coercive means are increasingly supplanting genuine diplomacy.
In light of these challenges, analysts and commentators have urged ASEAN to rethink its conflict management strategies. Recommendations include empowering ASEAN’s observer missions, establishing permanent peace monitoring cells, fostering cross-border community forums, and linking peaceful dispute resolution to broader economic initiatives. Such measures, proponents argue, would help transform ASEAN from a mere convener of dialogue into a guarantor of peace.
Ultimately, the 2025 Cambodia–Thailand border crisis serves as a stark reminder of the complexities of regional diplomacy in Southeast Asia. While the ceasefire brokered under ASEAN’s auspices has quieted the guns for now, the underlying issues of sovereignty, nationalism, and great-power rivalry remain unresolved. Whether ASEAN can adapt its cherished “ASEAN Way” to meet the demands of a changing geopolitical landscape will determine its future relevance—and the prospects for lasting peace in the region.
