Thailand watches border risks as armed forces upgrade firepower

Thailand’s armed forces are stepping up readiness and modernisation efforts as uncertainty grows over both land and maritime tensions with Cambodia, raising questions over whether the border could face another round of confrontation.

The latest signal came from Cambodian Senate President Hun Sen, who urged the Cambodian government not to rely on bilateral talks with Thailand to resolve maritime disputes following Thailand’s cancellation of MOU 44.

Instead, he called for the use of compulsory conciliation under the 1982 United Nations Convention on the Law of the Sea (UNCLOS) before moving to other processes.

Thai Prime Minister Anutin Charnvirakul has shown no particular concern, saying both sides are already aware of each other’s positions. Thailand, he said, would also use procedures under UNCLOS, although the exact form and timing of any talks have yet to be decided.

Thailand’s position appears to be that, if Cambodia refuses to return to bilateral negotiations, Bangkok has little reason to move first. The Thai side is seen as holding advantages across several areas, while no factor can force Thailand into arbitration without the consent of both countries.

Border incidents raise fresh concern

Tensions on land have also remained sensitive. The Second Army Region reported what it described as a provocative incident involving Cambodian soldiers in the O’Smach area near Chong Chom in Surin province on May 13. The area has allegedly been linked to scammer activity.

Thai forces reportedly detected 10 to 15 Cambodian soldiers and two foreign nationals moving close to the barbed-wire boundary area while filming video footage.

After verbal warnings were ignored, Thai soldiers fired two warning shots in line with security measures. The move was intended to prevent encroachment and deter actions that could breach the joint statement agreed in December 2025, while also reducing the risk of further tension along the border.

Later that evening, Cambodian soldiers reportedly fired 11 shots, beginning near Hill 278 east of the Chong Chom permanent border crossing in Kap Choeng district, before the gunfire moved along the eastern side of the road leading towards O’Smach.

Maj Gen Winthai Suvaree, spokesman for the Royal Thai Army, said senior Cambodian commanders and the Cambodian government often say one thing while actions on the ground suggest another.

Since the ceasefire, he noted, gunfire has continued to be heard, with some incidents involving explosion-like sounds, which Thailand views as provocative behaviour.

He claimed that similar incidents had occurred several times since the beginning of the year and had been reported along more than 400 kilometres of the Thai-Cambodian border.

Chinese suspect case remains under investigation

Another factor is the case of Sun Mingchen, a Chinese national arrested on firearms and explosives-related charges. Police have not found evidence that he planned to carry out sabotage in Thailand, but they have not ruled out the issue.

Sun reportedly held both Chinese and Cambodian passports and had travelled in and out of Thailand repeatedly since 2024, the year seen as the starting point of the latest phase of Thai-Cambodian tensions.

A search of his phone allegedly found footage linked to weapons training and military-style activity with Cambodian soldiers near Cambodia’s Special Forces 911 unit. Investigators also found alleged online queries related to sabotage and explosives.

Thai police are continuing to examine possible links and expand the investigation to determine whether others were involved.

Navy keeps watch on Cambodia’s maritime build-up

As the Thai government pushes diplomatically for Cambodia to accept bilateral negotiations, the armed forces are maintaining combat readiness for an uncertain border environment across both land and sea.

The services are working to integrate existing weapons systems while procuring replacements for equipment due to be retired.

In April, the Cambodian navy strengthened its maritime capability after receiving two Type 056 corvettes from China for patrol, coastal surveillance and maritime security operations. The vessels are equipped for close-range air defence, anti-ship operations and naval gunfire missions.

The Type 056 guided-missile corvette is docked at Pier 1 of Ream Naval Base, opposite Koh Kut in Trat province.

Although the Royal Thai Navy has said the development does not affect Thailand’s ability to protect its maritime sovereignty, as Thailand retains superior naval capability, it is monitoring Cambodia’s movements closely.

The Thai navy is also working to strengthen its own capabilities and is taking a more proactive approach, while remaining alert to Cambodia’s continued support from external military suppliers.

Progress has been made on the first frigate procurement project, covering one vessel starting in fiscal year 2026. The navy is selecting a private contractor from six companies across four countries that submitted documents.

The process must still go through contract preparation and signing, and is expected to be completed before Adm Pairote Fuangchan, Royal Thai Navy chief, retires on October 30.

However, due to budgetary pressure from several major defence procurement commitments, the Budget Bureau has asked that the second frigate procurement project be postponed to fiscal year 2028 to keep public debt within the government’s ceiling.

For the S26T submarine project, involving one vessel, the final payment is scheduled for fiscal year 2027. Delivery is expected in late 2028 or, at the latest, early 2029.

Air force accelerates fighter plans

The Royal Thai Air Force is also moving forward with its fighter replacement programme. ACM Seksan Kantha, Royal Thai Air Force chief, is monitoring progress on the first phase of the Gripen E/F fighter procurement project in Stockholm, Sweden, where the aircraft is entering production.

The air force is also preparing to adjust the second and third phases of its fighter procurement plan. Instead of acquiring four aircraft in each phase, it plans to combine both phases into a single project under the fiscal year 2028 budget and seek approval to buy eight aircraft at once.

The aim is to respond to changes in the global and regional security environment, as well as Thailand’s own threat assessments. The air force wants the aircraft to enter service sooner, by 2032, to replace F-16s that are being gradually retired.

Deterrence seen as key to future negotiations

Whatever direction Thai-Cambodian border tensions take, Thailand’s armed forces are expected to maintain enough capability to preserve the country’s advantage in any future negotiations over national interests.

One point remains clear: whenever the Thai-Cambodian border appears at risk of another flare-up, turmoil inside Thailand often emerges first. This was seen in 2011 and again in 2025, though the form may differ — from provocation and division to political interference, fake news or sabotage.