Governor of the National Bank of Cambodia Chea Serey (C-L) offers aid to a displaced resident (C) at a temporary camp set up at a pagoda during clashes along the Cambodia-Thailand border in Cambodia's Siem Reap province on December 11, 2025. Renewed fighting raged at the border of Cambodia and Thailand on December 11, with combat heard near centuries-old temples, ahead of an expected phone call from US President Donald Trump to the two nations' leaders. (Photo by TANG CHHIN Sothy / AFP)
THE nation has formally asked the UN Security Council to take urgent action over what it described as “a series of unprovoked and escalating armed attacks” by Thai forces along their shared border, elevating the dispute from a bilateral conflict to an international security issue.
In a Dec 10 letter to the Security Council president, Keo Chhea, Cambodian Permanent Representative to the UN, accused the Thai armed forces of violating the UN Charter, international humanitarian law and existing ceasefire and peace agreements by launching cross-border military operations into Cambodian territory.
The appeal comes after several days of intensifying clashes in border provinces, including Preah Vihear and Oddar Meanchey, with Cambodia alleging that Thai forces used heavy weapons, tanks, artillery, drones, warplanes and toxic smoke in attacks that extended into civilian areas.
“These military operations constitute a serious breach of the UN Charter, including the peremptory prohibition on the threat or use of force,” Keo Chhea wrote, warning that the situation now posed “a clear and present danger to regional peace and security”.
According to the letter, Thai forces opened fire on Cambodian positions on Dec 7 and escalated the assault early the following day with sustained bombardments across multiple locations.
Cambodia further alleged that the attacks later spread into non- combat civilian zones in Banteay Meanchey province and, as of Dec 10, into parts of Pursat and Battambang.
Cambodia claims the attacks have killed and injured civilians, destroyed homes and public infrastructure, and caused damage to protected heritage sites, including areas surrounding the Preah Vihear Temple, a Unesco World Heritage site long associated with border tensions between the two countries.
“Thailand’s deliberate and indiscriminate targeting of civilian areas constitutes a serious breach of international humanitarian law,” the letter said, citing the obligation to distinguish between civilian and military targets.
Phnom Penh also accused Thailand of violating the ceasefire agreement signed on July 28 and the Kuala Lumpur Peace Accord concluded on Oct 26, which committed both sides to resolve border issues peacefully and refrain from the use of force.
Keo Chhea said Cambodia remains committed to resolving disputes peacefully in line with international law and the UN Charter, noting that its forces exercised maximum restraint by withholding retaliation for 24 hours in respect of the ceasefire and the Kuala Lumpur Peace Accord, while reserving the right to self-defence under Article 51 of the UN Charter.
The letter referenced border demarcation agreements dating back to the 1904 and 1907 treaties between France and Siam, later upheld by the International Court of Justice and reaffirmed in the 2000 Memorandum of Understanding on boundary demarcation, which Thailand itself registered with the UN in 2011.
“Cambodia does not wish to be compelled into considering other means of response other than through diplomacy and dialogue,” Keo Chhea wrote.
The Cambodian government is asking the Security Council to condemn Thailand’s actions, demand an immediate cessation of military operations and call for full compliance with international humanitarian law.
It also requested the deployment of an independent UN fact- finding mission to investigate alleged violations and determine responsibility for civilian casualties and material destruction. — Phnom Penh Post/ANN
