Thailand-Cambodia Border Clash Escalates, Diplomatic Ties Severed

Soldiers from both nations exchanged heavy gunfire near the ancient Prasat Ta Muen Thom and Ta Moan temples, leading to civilian casualties, mass evacuations, and a complete collapse of diplomatic relations.

The latest hostilities were triggered by a landmine explosion earlier this week that injured five Thai soldiers, which Bangkok claims were newly planted by Cambodian forces. Phnom Penh vehemently denies the accusation, asserting the blast occurred on its territory due to remnants of past wars.

Timeline of the Escalation:

• May 2025: A Cambodian soldier is killed in a skirmish over contested territory, reigniting simmering tensions.

• This Week (July 21-23, 2025): A landmine blast injures five Thai soldiers in Ubon Ratchathani province, prompting Thailand to accuse Cambodia of breaching the Ottawa Treaty on anti-personnel mines. Cambodia denies the claim, stating the blast occurred on its side due to leftover unexploded ordnance.

• Wednesday, July 23, 2025: Thailand recalls its ambassador to Cambodia and announces the expulsion of Cambodia's envoy in Bangkok.

• Thursday, July 24, 2025:

  • In a reciprocal move, Cambodia also withdraws its diplomatic staff from Bangkok and orders Thai diplomats to leave Phnom Penh. Cambodia officially downgrades diplomatic relations with Thailand to their "lowest level."

  • Clashes erupt near the Ta Muen Thom and Ta Moan temples. Both sides accuse the other of firing first.

  • Thai army reports at least 12 Thai civilians killed and multiple injured from Cambodian artillery fire, including an eight-year-old boy. Most casualties reportedly occurred in Si Sa Ket province, where six people were killed after shots were fired at a gas station.

  • Thailand deploys F-16 fighter jets, with one reportedly bombing a Cambodian military target. Cambodia's Ministry of National Defence condemns this as "brutal and illegal military aggression," claiming Thai jets dropped bombs on Cambodian territory.

  • Thailand closes all border checkpoints with Cambodia and urges Thai nationals to evacuate Cambodia.

  • Cambodia's Prime Minister Hun Manet states Cambodia has "no choice but to respond with armed force against armed aggression."

  • Reports emerge of a Thai hospital (Phanom Dong Rak Hospital in Surin province) allegedly targeted by Cambodian artillery.

  • Approximately 40,000 Thai civilians from 86 villages near the border are evacuated.

• Friday, July 25, 2025: Reports indicate at least 16 people have been killed, with the majority being Thai civilians. One Thai soldier has also been confirmed dead. Casualties on the Cambodian side are less clear, with at least one civilian reported killed. Over 100,000 civilians have been displaced from both sides of the border.

Diplomatic Fallout and Regional Implications

With diplomatic ties rapidly deteriorating, both nations have imposed sweeping punitive measures. Cambodia has banned Thai imports including fruits, vegetables, electricity, internet services, and cultural content such as Thai dramas.

In response, Thailand has restricted cross-border land travel, halted tourist flows for gambling purposes, and suspended internet platforms used by Cambodian authorities. While humanitarian exemptions are being discussed, relations are now considered the worst they’ve been in more than ten years.

In response to the crisis, Cambodia has requested an urgent meeting of the United Nations Security Council.

Thailand's Political Struggle and Hun Sen Influence

The border crisis has unfolded amidst significant political instability within Thailand, while former Cambodian leader Hun Sen continues to exert considerable influence.

In Thailand, Prime Minister Paetongtarn Shinawatra is facing intense scrutiny and was recently suspended from office over an ethics probe linked to her handling of the crisis. A leaked phone call between her and former Cambodian leader Hun Sen, in which she reportedly called him "uncle" and dismissed a Thai commander, has further inflamed domestic divisions.

Critics accuse her of undermining the military, and a key coalition partner has since exited her government, adding to the fragility of her administration.

Despite stepping down as Prime Minister last year, Hun Sen continues to shape Cambodian affairs and its stance on the border dispute. His close ties with Prime Minister Paetongtarn Shinawatra, as evidenced by the leaked phone call, highlight his ongoing role in shaping Cambodia's foreign policy, even as his son, Hun Manet, now holds the premiership.

Hun Sen has publicly defended Cambodia's actions and condemned Thailand's "aggression," reinforcing a hardline approach to the border issue. Cambodia's recent announcement to revive mandatory military conscription, to be implemented next year, further underscores its preparedness for military confrontation.

Regional Challenge for ASEAN

The ongoing border clashes between Thailand and Cambodia have placed the Association of Southeast Asian Nations (ASEAN) under a critical spotlight, with experts debating its effectiveness in resolving internal disputes. While many argue that ASEAN's role is more vital than ever in de-escalating tensions, the current crisis also starkly exposes the limitations posed by its long-standing principle of non-interference.

ASEAN's foundational commitment to non-interference in the internal affairs of member states is a double-edged sword. While it promotes respect for sovereignty, it can also restrict the bloc’s ability to act decisively in situations like the Thai-Cambodian conflict.

Analysts note that ASEAN’s institutional structure and the lack of trust between the parties involved often prevent it from assuming a direct mediating role unless both countries formally request its assistance. Cambodia’s appeal for UN intervention—echoing a similar move in 2011—underscores a troubling lack of confidence in ASEAN’s capacity to manage conflict within its own region.

Nonetheless, some experts believe ASEAN can still play a critical role by offering a platform for informal dialogue and confidence-building measures, even if direct mediation proves difficult. The current ASEAN chair, Malaysia, has openly called for de-escalation, stressing that peace is the only option available.

Malaysian Prime Minister Anwar Ibrahim reached out to both Cambodian Prime Minister Hun Manet and Thailand’s acting Prime Minister Phumtham Wechayachai.

Anwar confirmed that he has relayed messages to both leaders, urging them to “stand down” and engage in negotiations. His proactive approach, particularly in his capacity as ASEAN chair, signals a strong desire within the bloc to facilitate a peaceful resolution. While the details of these exchanges remain confidential, they represent a vital channel for communication amid rising tensions.

Global Peace Rise, Thailand Rejects Mediation

Singapore's Ministry of Foreign Affairs released a statement calling on both parties to de-escalate tensions through diplomatic means. "Singapore is deeply concerned by the clashes, and calls on both countries to exercise restraint and cease hostilities."

The Philippines' Department of Foreign Affairs echoed the same concern: "We urge both parties to extend due consideration and care to innocent civilians who may be affected by the ongoing conflict." Manila also emphasised the importance of diplomacy by encouraging open communication between Cambodia and Thailand.

Viet Nam called on both countries “to not use force” and to “peacefully and satisfactorily resolve disagreements on the basis of fundamental principles of international law, the United Nations Charter, the ASEAN Charter, the Treaty of Amity and Cooperation in Southeast Asia.”

Japan also reminded Bangkok and Phnom Penh of the importance of their diplomatic relationship for “peace and stability in the region,” urging both leaders to return to the table and resolve matters through peaceful dialogue.

China, a strong partner to both Cambodia and Thailand, stated that Beijing would adopt a “fair and impartial position” in the clashes.

Chinese Foreign Ministry spokesman Guo Jiakun said, “Good neighbourliness and properly handling differences are in line with the fundamental and long-term interests of both sides."

Beijing “has and will continue to, in its own way, do its best to promote peace and dialogue, and play a constructive role in promoting the easing and cooling down of the situation,” he added.

Meanwhile, the United States has urged both countries to halt hostilities, stressing restraint, dialogue, and civilian protection. It expressed condolences and called for diplomacy to prevent further violence.

However, Thailand has rejected all offers of third-party mediation, insisting the dispute be resolved through bilateral talks and calling on Cambodia to halt its attacks first.

Thai Foreign Ministry spokesperson Nikorndej Balankura told Reuters, “I don’t think we need any mediation from a third country yet,” adding, “We stand by our position that a bilateral mechanism is the best way forward—this is a confrontation between two countries. Our doors are still open.”

The Cambodian government has yet to respond to the statement.

The long-standing border dispute—particularly around the 1,000-year-old Preah Vihear temple, awarded to Cambodia by the International Court of Justice (ICJ) in 1962—remains a persistent flashpoint. While Thailand acknowledges the 1962 ruling on the temple’s sovereignty, the precise demarcation of the surrounding border area remains unresolved and highly volatile.

In 2013, the ICJ clarified its earlier judgment, affirming Cambodia’s sovereignty over the entire promontory of Preah Vihear and ordering Thailand to withdraw all military forces from the area.

However, Thailand does not accept the general compulsory jurisdiction of the ICJ and has not done so since 1960. This means any legal dispute involving Thailand at the ICJ requires its specific consent, on a case-by-case basis.

This legal stance has resurfaced as Cambodia recently submitted a new request to the ICJ concerning other contested areas, including the Emerald Triangle (Mom Bei), and the Ta Moan Thom, Ta Moan Tauch, and Ta Krabei temples.

Despite the ICJ’s clarifications and Cambodia’s renewed call for judicial intervention, nationalist sentiments on both sides continue to fuel tensions—marking today's escalation as a dangerous new chapter.

The AMC's Cambodia expert:

https://www.asiamediacentre.org.nz/experts/sungyonglee

Banner image: c/o Royal Thai Army

-Asia Media Centre