Thailand-Cambodia Conflict

The Thailand-Cambodia conflict is a long-running, unresolved border dispute between Thailand and Cambodia that escalated into sustained armed conflict in the second half of 2025, resulting in more than 100 deaths and the displacement of more than half a million civilians. It emerged from competing claims to ancient temples and their surrounding land, particularly the temples of Preah Vihear and Ta Muen Thom. Fighting intensified in late July and spread to at least 12 border sites before a ceasefire was announced on July 28 in Putrajaya, Malaysia, following talks mediated by Malaysia and encouraged by the United States and China. The agreement proved short-lived, however, as heavy fighting resumed in early December. A second ceasefire agreement was reached on December 27 following mounting pressure from the international community, though its durability remained uncertain.

Background

Contested cultural and territorial claims

The roots of the conflict lie in centuries of cultural rivalry, colonial-era treaties, and contested territorial claims over temples on the border. From the 9th to the 15th century, the Khmer (Cambodian) empire dominated much of mainland Southeast Asia, including large parts of modern Thailand, Laos, and Vietnam, profoundly influencing the region’s art, architecture, and political traditions.

As the Khmer empire declined, the Siamese (Thai) kingdom of Ayutthaya rose to power, sacking the Khmer capital of Angkor in the 15th century, seizing western Cambodian territories, and adopting Khmer cultural forms. By the late 16th century, Cambodia found itself caught between two stronger neighbors, Siam to the west and Vietnam to the east, and survived under shifting vassalage to both. This instability continued until the 19th century, when Cambodia became a French protectorate and later part of French Indochina. Cambodia would not regain independence until 1953.

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Thailand’s independence during the colonial era and its continued relative stability have allowed it to outpace Cambodia economically; in comparison, Cambodia endured French colonization, U.S. bombing during the Vietnam War, and the Cambodian genocide under the Khmer Rouge regime. In recent decades, tensions have flared as Cambodians accuse Thais of cultural appropriation, claiming that key aspects of Thai culture originate from Khmer traditions, including much of Thai art and architecture as well as the martial art Muay Thai, which is said to be derived from its Cambodian equivalent, Kun Khmer. Thais counter that any such cultural exchanges occurred centuries ago and that Thailand’s historical conquests justify claims to certain border areas. This rivalry continues to shape nationalist sentiment and political discourse in both countries.

French-era borders and the Temple of Preah Vihear

After France established a colonial presence in Southeast Asia with its Cochinchina colony (southern Vietnam), Cambodian King Norodom accepted French protection (effectively colonial control) in 1863. Though pressured into the agreement, he likely regarded the move as a necessary measure to maintain Cambodian sovereignty. Cambodia suffered exploitation under French rule, but historians generally agree that it prevented Cambodia from being entirely absorbed by Siam and Vietnam.

France soon consolidated control and forced Siam to cede territory, culminating in the 1907 Franco-Siamese treaty, which defined much of the modern borders between Thailand, Cambodia, and Laos (then under French control). The treaty returned Battambang, Siem Reap, and Serei Saophoan, as well as the Temple of Preah Vihear and other border areas, to Cambodia. This outcome remains a source of resentment in Thailand.

During World War II, Thailand, allied with Japan, reclaimed much of the territory lost in 1907, including the Temple of Preah Vihear, but returned it to France in 1946 as a condition for joining the United Nations. Following Cambodia’s independence in 1953, Thai troops reoccupied the Temple of Preah Vihear, prompting Cambodia to take the dispute to the International Court of Justice (ICJ) in 1959.

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In 1962 the ICJ ruled that the Temple of Preah Vihear belonged to Cambodia but left the status of the surrounding land ambiguous, setting the stage for future disputes. The temple remained largely inaccessible during Cambodia’s decades of turmoil, not reopening to visitors until the 1990s.

Tensions resurfaced in 2008 when Cambodia registered the Temple of Preah Vihear as a UNESCO World Heritage site. Thailand protested, and border clashes between 2008 and 2011 left at least 20 people dead and displaced thousands. Cambodia again appealed to the ICJ, seeking clarification of the 1962 ruling. The court initially called for all troops to be withdrawn from the area (which was done in 2012), and in 2013 the court confirmed that the temple and its immediate vicinity lay within Cambodian territory.

May 28 skirmish

On May 28, 2025, a skirmish near the Temple of Preah Vihear left a Cambodian soldier dead. Both sides blamed the other for initiating the violence. The incident triggered months of tension and retaliation: Cambodia banned Thai goods, including food and fuel, while Thailand closed border crossings and restricted Internet and power links to Cambodia.

Paetongtarn steps down

The conflict soon destabilized Thai politics. Prime Minister Paetongtarn Shinawatra was suspended from office after the leak of a June 15 phone call with Cambodian leader Hun Sen in which she referred to the Thai military as the “opposite side” and addressed Hun Sen as “uncle.” Critics saw this as undermining national unity and showing deference to a rival leader. Protests erupted, and the Bhumjaithai Party withdrew from her coalition, leading to her suspension by the Constitutional Court.

Hun Sen later stated that he had recorded the conversation and shared it with 80 Cambodian officials, leading to its leak, in what observers widely regarded as a deliberate attempt to undermine Paetongtarn’s image and leadership. These developments exposed the deteriorating relationship between Thailand’s Shinawatra family and Cambodia’s Hun family, both powerful political dynasties. Thaksin Shinawatra, a billionaire former Thai prime minister and Paetongtarn’s father, once enjoyed close ties with Hun Sen, who served as Cambodia’s prime minister from 1985 to 2023 and now serves as Senate president while his son Hun Manet serves as prime minister.

Escalation in late July

The situation escalated dramatically in late July. On July 23 a Thai patrol in Ubon Ratchathani province triggered a land mine on the border, injuring five soldiers. Thailand accused Cambodia of laying new mines and downgraded diplomatic relations, which led to both countries recalling their ambassadors.

On July 24 fighting broke out near the Temple of Ta Muen Thom, and over the next few days clashes occurred across 12 border locations. Gunfire, artillery, and rockets were exchanged, while Thai air strikes targeted Cambodian positions. Martial law was declared in several Thai border districts. Civilian areas were hit on both sides, including hospitals in Thailand and, according to Cambodian officials, a school in Cambodia.

Thaksin Shinawatra posted on X that the Thai military needed to “teach Hun Sen a lesson for his cunningness.” Hun Sen later responded by accusing Thaksin of betrayal and of fueling war. Media outlets highlighted the increasing familial animosity as worsening the volatility of the border conflict.

July ceasefire and its breakdown

ASEAN, chaired by Malaysia in 2025, called for an immediate ceasefire, and the United Nations Security Council held an emergency session on July 25. On July 26 U.S. Pres. Donald Trump announced that both sides had agreed to work toward a ceasefire, though fighting persisted. Thailand and Cambodia later confirmed attendance at July 28 talks in Putrajaya, where they declared an “immediate and unconditional” ceasefire.

Relations deteriorated again within months. On November 11 Thailand announced that it would halt implementation of the ceasefire after several of its soldiers were injured in a land-mine explosion along the border. Cambodia denied laying new land mines, though independent assessments suggested that the mines appeared relatively new, leaving the circumstances around the incident unclear. The following day, at least one person was killed in Cambodia amid renewed gunfire, and the two countries accused each other of shooting first.

More serious military exchanges resumed in early December. On December 8 Thailand launched air strikes in the border region, stating that it was targeting Cambodian military facilities believed to house long-range artillery. A Thai foreign ministry spokesperson stated that Cambodia had “trampled” the ceasefire agreement, while a Thai general said that the aim was to cripple Cambodia’s military capacity. Within hours, hundreds of thousands of civilians were being evacuated. Fighting continued and intensified over the following weeks, with air strikes, drone attacks, and ground clashes reported at numerous locations.

By late December Thailand reported that 26 soldiers and one civilian had been killed during the month’s fighting. Cambodia did not release an official figure for military casualties but stated that at least 30 civilians had been killed and 90 injured. Independent estimates suggested that at least 101 people had been killed and more than half a million had been displaced during the renewed hostilities in November and December.

December 27 ceasefire

On December 27 Thailand and Cambodia announced a new 72-hour ceasefire. The agreement called for an immediate halt to military operations and declared mutual commitments to clearing land mines along the border, which had been a trigger for escalation in the previous weeks. In the following days, Thai and Cambodian diplomats met in China with Chinese Foreign Minister Wang Yi, whose office described the ceasefire as “hard-won” and urged both sides to “rebuild political mutual trust.” After the ceasefire held for its initial 72-hour period, Thailand released 18 Cambodian soldiers as a confidence-building measure.