Ubon Ratchathani province in the context of Yasothon province

Following the territorial dispute between Cambodia and Thailand in 2025, tensions escalated in several contested areas along the Cambodia–Thailand border, particularly during the Emerald Triangle clashes on May 28. After a series of diplomatic and political incidents, the crisis erupted into open armed confrontation on July 24. Thailand and Cambodia subsequently agreed to an unconditional ceasefire on July 28.

The situation intensified on July 23, when a Thai soldier was seriously injured after stepping on a PMN-2 anti-personnel landmine in Nam Yuen district of Ubon Ratchathani province. The incident triggered renewed hostilities, and the following day, direct armed clashes erupted across several sectors of the frontier. Both nations claimed to be acting in self-defence, while exchanges of artillery and small-arms fire were reported along a 40-kilometre stretch of the border. Heavy fighting displaced more than 200,000 civilians, many of whom sought refuge in temporary shelters and schools across northeastern Thailand and northern Cambodia.

The Emerald Triangle is the shared border region between Cambodia, Laos and Thailand. It includes the area of Chong Bok (Thai: ช่องบก), a mountain pass through the Dangrek Range, which forms much of the natural boundary between Thailand and Cambodia. In Cambodia, the area is known as Mom Bei (Khmer: មុំបី).

The Emerald Triangle name was coined in 2000 as a project for international cooperation to promote tourism and economic development in the area. The name, referring to the area's lush environment, is a play on the pre-existing Golden Triangle region between Laos, Thailand and Myanmar. In the broader sense, the Emerald Triangle covers areas in seven provinces among the three countries: Preah Vihear, Oddar Meanchey and Stung Treng in Cambodia, Salavan and Champasak in Laos, and Ubon Ratchathani and Sisaket in Thailand. In the narrow sense, it refers to the boundary tripoint between the three countries, which lies near the Chong Bok pass. The pass has an elevation of 330 metres (1,080 ft).

Nam Yuen (Thai: น้ำยืน, pronounced [náːm jɯ̄ːn]; Northeastern Thai: น้ำยืน, pronounced [nâːm jɯ̄ːn]) is the southernmost district (amphoe) of Ubon Ratchathani province, northeastern Thailand.

The territorial dispute between Cambodia and Thailand escalated into a direct armed confrontation on 24 July 2025 along the Cambodia–Thailand border. Although both governments subsequently agreed to an unconditional ceasefire on 28 July 2025, hostilities later resumed in December, during which Thai forces seized several towns and strategic hills in contested areas near the frontier.

Tensions had sharply increased on 23 July, when a Thai soldier was seriously injured after stepping on a PMN-2 anti-personnel landmine in Nam Yuen district, Ubon Ratchathani province. The incident served as the immediate trigger for wider hostilities. On the following day, direct armed clashes erupted across multiple sectors of the border. Thai media widely reported that Cambodia's BM-21 multiple rocket launchers, which struck Thai residential neighbourhoods, a hospital, and a gas station, acted as the catalyst for the outbreak of full-scale fighting on 24 July 2025. Both sides asserted that their actions were taken in self-defence and accused the other of initiating the conflict. The clashes resulted in the displacement of more than 200,000 civilians across northeastern Thailand and northern Cambodia.