CW Note

CWA # 1833
CW Note
Thailand and Cambodia: A joint declaration, US-ASEAN intervention and its challenges

Neha Tresa George
31 October 2025

Photo Source: AP Photo

In the news
On 26 October, the Prime Ministers of Thailand and Cambodia, Anutin Charnvirakul and Hun Manet, signed a joint declaration at the sidelines of the ASEAN summit in Malaysia. Both upheld the principles of “peace, security, stability and prosperity in the regions” and agreed to carry out “military de-escalation,” shift the heavy, destructive weapons and remove the mines along the border. Thailand announced the release of 18 prisoners of war.

The deal was brokered by US President Donald Trump and Malaysia’s Prime Minister Anwar Ibrahim, who is also the current President of ASEAN. Referring to the declaration as a “peace treaty,” Trump said: “The United States will have robust commerce and cooperation, transactions, lots of them, with both nations, as long as they live in peace.”

On 26 October, Thailand’s Ministry of Foreign Affairs stated that the declaration did not constitute a peace deal, but rather an attempt to normalise tensions with Cambodia

On 27 October, Thai Prime Minister Anutin denied border reopening from 1 November. He explained that it would depend on Cambodia’s implementation of the terms in the joint declaration. 

Issues at large
First, a historical background to the Thai-Cambodia border conflict. It can be traced to the French colonial rule. Using the French map of 1907, Cambodia claimed three areas - Preah Vihar, Ta Muen Thom and Ta Krabey, resulting in contestation with Thailand. These three areas are culturally significant for both countries. In 1962, the ICJ ruled in support of Cambodia’s claims over the Preah Vihear temple; however, Thailand continued to exert its influence over the peripheries excluded from the ruling. In February 2025, Thai soldiers refused Cambodian tourists singing their national anthem at Prasat Ta Muen Thom, resulting in fresh clashes this year. Despite high-level meetings, there were air strikes, landmine blasts and clashes resulting in casualties, border closures, and the evacuation of more than 3,00,000 civilians. While Thailand seeks to resolve the issue bilaterally through the Joint Border Committee, Cambodia internationalises it by approaching the UNSC. 

Second, recurring clashes since Cambodia’s independence in 1953. Although Thailand accepted the ICJ ruling in 1962, relations deteriorated in 2008 when Preah Vihear became a UNESCO World Heritage site at Cambodia’s request. The weeklong clashes in 2011 halted with the ceasefire agreement and opening of border checkpoints. In 2013, the ICJ reconfirmed Cambodia’s sovereignty over Preah Vihar, ordering the withdrawal of Thai soldiers. Between 2014 and 2024, there were short-term clashes along the border. However, the five-day battle in July 2025 concluded with an unconditional ceasefire on 28 July with the support of the US, Malaysia, and China, paving the way for the Joint Declaration. 

Third, the role of Malaysia and ASEAN. Though founded on the principles of “non-interference, sovereign equality and consensus decision making,” as the current chair of ASEAN, Malaysia has played a significant role in promoting the ceasefire and the Joint Declaration between Thailand and Cambodia. ASEAN has been at the forefront, facilitating meetings, circulating statements and supporting Malaysia’s efforts. ASEAN Observer Team (AOT), comprising ASEAN defence attachés, is monitoring the implementation of the peace process. The ASEAN Foreign Ministers also recommended the ASEAN Charter and the Treaty of Amity and Cooperation as the basis of conflict resolution between Thailand and Cambodia. 

Fourth, Trump and the US influence through trade negotiations. The US President Trump has been an active influencer in the negotiations. The exports of the countries are heavily dependent on the US market. Trump used the trade factor to negotiate between them. In July, he threatened to end trade relations with both countries if a ceasefire is not reached. At the ASEAN summit, Trump entered into trade agreements with Cambodia and Malaysia. He also announced a framework for trade, along with a Memorandum of Understanding on minerals with Thailand. 

In perspective
First, the ambiguity over the Joint Declaration. While the officials of Thailand have regarded the declaration as the path towards peace, Trump referred to it as the “peace agreement.” This difference in interpretations could lead to future ambiguities regarding the implementation of the terms under the declaration. 

Second, the dominance of external influence over ASEAN. Due to the passivity and non-interventionist nature of ASEAN, the Thailand-Cambodia conflict saw the dominance of external powers, such as the US and China. They have been instrumental in pressurising the countries to reach a consensus on the ceasefire and the Joint Declaration. This indicates that the facilitative role of ASEAN has been insufficient to have a significant impact on the conflict. 

 

About the authorNeha Tresa George is a postgraduate student at TISS, Hyderabad.

 

 

 

 

 

 

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