Thailand-Cambodia: Border disputes, blame game and a fragile ceasefire

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CWA # 1876

CW Note

Thailand-Cambodia: Border disputes, blame game and a fragile ceasefire

Akshath Kaimal
18 December 2025

In the news
On 7 December, Thailand and Cambodia traded blame for a brief armed encounter along the border near Sisaket province. The Thai army said that it retaliated after Cambodian fire injured two of its soldiers.

On 12 December, fighting between the countries entered its fifth day as Thai Prime Minister Anutin Charnvirakul said that he was scheduled to speak to US President Donald Trump.

On 13 December, President Trump announced a ceasefire, writing: “They have agreed to CEASE all shooting effective this evening, and go back to the original Peace Accord made with me, and them, with the help of the Great Prime Minister of Malaysia, Anwar Ibrahim.” Thailand rejected the claim, but Cambodian Prime Minister Hun Manet said his country “supported the ceasefire initiative of Malaysia, with Washington's participation.”

On 14 December, Thailand protested with the United Nations human rights agency, accusing Cambodia of launching indiscriminate attacks, including on non-military targets, resulting in the first civilian death from the conflict.

On 16 December, Thai Prime Minister Anutin Charnvirakul said of Trump’s ceasefire proposal that he “should ask Cambodia to stop firing at Thailand first, because Thailand has never fired first."

Issues at large
First, a brief background to the conflict. Thailand and Cambodia have been embroiled in a border conflict since the latter was under French colonial rule. The primary site of tensions is the Preah Vihear temple in the Dangrek Mountain range, which acts as a natural border between the two countries. Two Franco-Siamese treaties in 1904 and 1907 demarcated the border between the two countries, with the Preah Vihear temple falling inside Cambodia - a proposal Thailand (then Siam) claims it never accepted. Cambodia took the issue to the International Court of Justice (ICJ) in 1959, which ruled in its favour in 1962. Tensions reignited in 2008 when Cambodia nominated the temple as a UNESCO World Heritage Site, which led to skirmishes along the border. In July 2025, hostilities began again, killing at least 48 people. US President Donald Trump and the Association of Southeast Asian Nations (ASEAN) helped broker a ceasefire between the two countries, but it did not hold as they began fighting again on 7 December.

Second, a fragile ceasefire. Although a US-brokered ceasefire was reached between Thailand and Cambodia in July 2025, the core issue of the conflict was not addressed. Although the ICJ had ruled in 1962 and 2011 that the Preah Vihear temple belonged to Cambodia, several other regions near the border remain disputed. Hence, a deal aimed at only halting hostilities meant any ceasefire between the two countries would be fragile. Additionally, Thailand had initially rebuffed President Trump’s efforts to mediate, but folded once Trump threatened to increase tariffs on the country. This indicates that the US used its leverage to force a ceasefire, rendering it vulnerable. The ceasefire also did not address the issue of landmines, as Cambodia is one of the most heavily mined countries. The landmine issue reignited hostilities after an explosion injured a Thai soldier in November.

Third, Trump’s intervention. President Trump has portrayed himself as a “global peacemaker,” touting his role in mediating a truce in several conflicts, including between Thailand and Cambodia. He even claimed through a Truth Social post that a “roadside bomb” had killed and wounded Thai soldiers by accident, which the Thai PM firmly denied. He also announced a second ceasefire following the outbreak of hostilities in December, which both countries disagreed on. Trump recently said that he would be able to stop hostilities “pretty quickly,” suggesting that the core issues of the conflict relating to border issues and landmines would not be addressed again.

Fourth, ineffective ASEAN. While the US played a major role in securing a ceasefire when hostilities broke out in July, the truce was made in collaboration with ASEAN. The bloc agreed to monitor the ceasefire along the Thai-Cambodian border, but details of this effort were sparse. With hostilities breaking out again in December, it is clear that ASEAN’s efforts to monitor the ceasefire were ineffective. Additionally, the July ceasefire agreement not only ignored the long-standing border issue between the countries but also failed to address the landmine issue and transnational cybercrime, which has been exploding in Southeast Asia, with Cambodia at its epicentre.

In perspective
The unresolved issues on the border with the landmine problem and a lack of commitment from the conflict parties to the ceasefire, added with larger-scale cybercrime operations, imply that the conflict between the two countries is unlikely to cease any time soon. Meanwhile, Trump has been keen on being the primary peacemaker and even used the threat of tariffs to get both countries to stop fighting in July. But with both countries nearing a trade deal with the US, he could have less leverage this time around. Besides, ASEAN’s inability to address the core issues of the conflict, while also being unable to prevent hostilities from breaking out, shows its ineffectiveness. In sum, the border conflict between Cambodia and Thailand is likely to continue unless there is a breakthrough.

About the author
Akshath Kaimal is a Research Intern at NIAS.

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