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Deadly Thai-Cambodian dispute puts Asean’s relevance on the line

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People rest at a shelter, following recent clashes along the disputed border between the two countries, according to authorities people have been killed across three border provinces, in Surin province, Thailand, July 24, 2025. REUTERS/Pansira Kaewplung TPX IMAGES OF THE DAY

People rest at a shelter, following recent clashes along the disputed border between the two countries, in Surin province, Thailand, on July 24.

PHOTO: REUTERS

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  • Tensions escalate between Thailand and Cambodia over a border dispute, with casualties and accusations of aggression from both sides.
  • Malaysia, as Asean chair, calls for a ceasefire and offers to mediate, after Cambodia had sought UN intervention.
  • Experts say Asean's credibility is challenged due to lack of trust and structural issues, potentially opening the door for China to mediate.

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SINGAPORE – The deadly border dispute between Thailand and Cambodia is once again testing Asean’s longstanding principle of non-interference, say analysts.

Clashes between its two member states on July 24

left at least 12 dead, following two months of brewing border hostilities.

The sharp escalation underscores Asean’s limitations in handling intra-regional disputes, experts told The Straits Times, and raises fresh questions about its relevance in managing crises among its own members.

The regional grouping has a narrow window in which to act, said Ms Joanne Lin, a senior fellow at the ISEAS – Yusof Ishak Institute, arguing that neutral members could potentially step in to broker talks or quietly facilitate de-escalation.

Malaysian Prime Minister Anwar Ibrahim said late on July 24 that he has spoken to Cambodia Prime Minister Hun Manet and Thailand’s Acting Prime Minister Phumtham Wechayachai.

Datuk Seri Anwar said he appealed, in Malaysia’s capacity as the current Asean chair, to both leaders for an immediate ceasefire to prevent further hostilities and to create space for peaceful dialogue and diplomatic resolution.

“I welcome the positive signals and willingness shown by both Bangkok and Phnom Penh to consider this path forward,” Mr Anwar said in a social media post. “Malaysia stands ready to assist and facilitate this process in the spirit of Asean unity and shared responsibility.”

Until Mr Anwar’s comment late on July 24, the conflict had not been publicly raised – not even at the recent Asean Foreign Ministers’ Meeting in Kuala Lumpur.

When asked about the issue during a press conference on July 11, Malaysia’s Foreign Minister Mohamad Hasan called it a bilateral issue and reaffirmed the group’s traditional stance of non-interference.

Mr Anwar’s comments came hours after a network of parliamentarians from Asean called for “immediate diplomatic intervention”, and for Malaysia as the Asean chair to secure a ceasefire, establish protected humanitarian corridors and relaunch direct talks between Thailand and Cambodia.

It is unclear what further steps Asean can or will take to help resolve the spat between two of its members.

The current flare-up began in May, when a

Cambodian soldier was killed during a brief exchange of gunfire.

Tensions have steadily escalated since, culminating in the recent air strikes and cross-border shelling.

At least 12 Thais, mostly civilians, have been killed in the latest outbreak of violence amid a longstanding border dispute. Fighting erupted in a contested area, with Cambodia accused of firing rockets into a Thai village and attacking a hospital, while Thailand launched air strikes on Cambodian military targets.

In response, Thailand has closed its entire border and urged its citizens to leave Cambodia.

Phnom Penh has downgraded diplomatic ties, accusing Bangkok of using excessive force.

Asean’s credibility has taken a further hit as Cambodia seems to have bypassed the grouping by appealing directly to the United Nations.

On July 24, the Cambodian media published Prime Minister Hun Manet’s letter to the UN Security Council’s president, Pakistan’s envoy Asim Iftikhar Ahmad, calling for an urgent meeting of the 15-member body.

It is the first time in more than a decade that an Asean member has made such a request.

Cambodia also made the previous request in 2011, when artillery exchanges with Thailand near the Preah Vihear temple prompted Phnom Penh to seek international intervention.

The UN Security Council is expected to convene in the coming days, but observers say any outcome will likely mirror that of 2011, which had included calls for maximum restraint and for Asean to play a more active role in dispute resolution.

Still, the referral itself is telling.

If countries in the region feel compelled to turn to New York to manage tensions with their neighbours, it reflects a worrying lack of trust in Asean, or in any regional third party, to help defuse a conflict in its own backyard.

“The gap between Asean’s aspirational vision and its operational readiness has rarely been this exposed; and I am worried that the current geopolitical contour will make it more frequently exposed,” said Mr Andrew Mantong, a researcher at Indonesia’s Centre for Strategic and International Studies (CSIS).

Cambodian soldiers reloading the BM-21 multiple rocket launcher in Preah Vihear province on July 24, amid border hostilities with Thailand.

PHOTO: AFP

Trust a key issue?

Some analysts say a key factor holding Asean back is the lack of trust between the parties involved. Asean Secretary-General Kao Kim Hourn is Cambodian, and some observers argue that Thailand may not view him as a neutral mediator.

A similar impasse occurred in 2008, when Cambodia rejected mediation by then Asean secretary-general Surin Pitsuwan, a veteran Thai diplomat, during border clashes near the Preah Vihear temple.

After mediation failed, the conflict simmered without formal resolution, until 2011, when Cambodia turned to the UN following renewed violence at the same border area.

However, others say the problem is structural, not personal. Ms Lin said the issue lies with Asean’s institutional design, not the nationality of its representatives.

“The Secretariat does not have the mandate to lead politically, and decisions must come from member states,” she said, noting how back in 2011, Cambodia had similarly turned to the UN.

Eventually, the case went to the International Court of Justice, which ruled in 2013 that Cambodia had sovereignty over the temple and ordered Thai troops to withdraw.

That verdict helped ease tensions, but more than a decade on, diplomatic relations between the two neighbours are at their lowest in years.

Bilateral channels, said Ms Lin, may no longer be viable.

Still, she believes that third-party members like Indonesia or Singapore could potentially mediate.

In the last bout of fighting between the two countries in 2011 – when Indonesia was the Asean chair – then Indonesian foreign minister Marty Natalegawa undertook shuttle diplomacy to defuse tensions.

He held talks with both sides in their respective capitals, and also subsequently met with the UN Security Council alongside the two nations’ foreign ministers.

With the current ignition of tensions, Ms Lin said, “if Asean doesn’t step up, it risks being sidelined in its own region. China, which has close ties with both countries, has already shown interest in stepping in”.

China on July 24 expressed deep concern over the border clashes and offered to play a constructive role in promoting peace, urging both sides to resolve the dispute through dialogue and pledging to remain fair, impartial and supportive of regional stability.

Asean would prefer that the two countries resolve the conflict bilaterally, as both are members of the regional organisation.

But if that is not possible, they should resolve it peacefully through third-party mediation, said Dr Mustafa Izzuddin, a senior international affairs analyst at business consultancy Solaris Strategies Singapore.

The group has faced criticism for its failure to implement the five-point peace plan with Myanmar’s military regime, as well as its inability to conclude negotiations on a code of conduct for the South China Sea, aimed at managing tensions amid overlapping maritime claims.

“Asean is acting strategically so that it does not need to bite off more than it can chew as a multilateral organisation with a multitude of interests that are focused on regional integration,” said Dr Mustafa.

  • Additional reporting by Bhavan Jaipragas

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