Escalation Without Remorse: Thailand’s War of Choice and Cambodia’s Fight for IHL Accountability

Editorial – Traju Bulletin Team

War has not returned to Southeast Asia by accident. Along the Thai–Cambodian border in 2025, conflict has unfolded not as the inevitable outcome of ancient disputes but as the product of deliberate choices made by Thailand’s leadership. The global news record reveals an unmistakable pattern: Thailand escalates, Cambodia restrains. One side turns to diplomacy; the other turns to F-16s.

The first clash came on 28 May 2025, when a Cambodian soldier was killed in a brief firefight inside disputed territory.¹ Cambodia’s initial response was not retaliation, but law: Phnom Penh signaled its intention to seek an answer from the International Court of Justice, affirming that boundaries must be settled through rules, not rockets.² Thailand, meanwhile, reinforced its forward positions.

The truth of this conflict emerged fully in late July. The truth of this conflict emerged fully in late July, when over five days Thailand escalated to the use of fighter jets and heavy artillery. According to Reuters, Thailand deployed F-16 jets on July 24 and the clashes intensified on July 25 with heavy artillery and rocket fire across multiple frontlines. The fighting that followed killed at least 48 people, most of them civilians, and displaced an estimated 300,000 residents.³⁻⁵ Cambodian children fled schools; rural families escaped bombardment with only clothes on their backs. The scale of the displacement, documented by multiple international outlets, shows that this was not a “clash,” it was a war, and Thailand chose overwhelming force.

The asymmetry in capacity, decision-making and consequence cannot be ignored. Thailand’s use of advanced combat aircraft in populated border zones raises fundamental concerns under International Humanitarian Law (IHL).

The ceasefire that followed in October, reached only after pressure from Malaysia, China and the United States, was the closest the region has come to peace this year.⁶ Yet while Cambodia implemented de-escalation commitments, tensions surged again in November. After a landmine blast wounded Thai soldiers, which Phnom Penh said was due to old, unmapped mines, Bangkok threatened to suspend the truce and opened fire again.⁷

Worse still, a Cambodian woman reported she had been raped by Thai soldiers while attempting to cross the border.^8⁻9 Over 200 civil society organizations demanded accountability.¹⁰ Sexual violence in an armed conflict is not an “incident,” it is a war crime. Thailand’s immediate response, blanket denial, was not the behaviour of a state committed to justice.

Then came 7 December, a new and chilling escalation. Thai ground forces intensified cross-border fire along the Preah Vihear and Oddar Meanchey sectors, prompting urgent alerts from Cambodian local authorities.¹¹ Cambodia did not respond militarily. For more than 24 hours, Phnom Penh maintained a posture of restraint, calling on Thailand to cease its attacks and return to negotiation channels established under the October ceasefire.¹² But instead of de-escalation, the next morning, 8 December, Thailand launched F-16 airstrikes into Cambodian territory, killing civilians, destroying homes, and triggering mass evacuations.¹³This sequence matters: Cambodia absorbed a full day of Thai attacks before the first airstrike was ever launched, demonstrating clearly which side chose escalation and which side chose patience.

Thai commanders openly declared their goal:

to “cripple Cambodia’s military capability” for the future.¹⁴

Openly seeking to permanently degrade another state’s defensive capacity, outside of any imminent attack, is not self-defence under international law. It is aggression.

The consequences are humanitarian first. Tens of thousands of Cambodian women, children and elderly people have now been uprooted, some twice in a single year.¹⁵ Civilians are not just in the way of this conflict; they are its primary victims.

Thailand argues its operations are necessary to neutralise security threats. But IHL does not permit ends to justify means. Three legal standards apply:

Distinction: Attacks must target only combatants and military infrastructure — not pagodas, schools, homes or clinics.
Proportionality: Civilian harm must never be excessive relative to the military advantage gained.
Precautions: Every feasible measure must be taken to minimise civilian injury.

This war has cast doubt on Thailand’s respect for all three.

The world must recognise what Cambodia has demonstrated: restraint is not weakness, it is principle. Phnom Penh has repeatedly asked for dialogue, declaring it is “ready at any time” for talks.¹⁶ Thailand refused immediate negotiations, while continuing its military campaign.

If verified by impartial investigation, Thailand’s actions create state responsibility and individual criminal liability, including for war crimes under the jurisdiction of the International Criminal Court, which extends to Cambodian territory regardless of the perpetrator’s nationality. Laws exist for moments like this. The question is whether the international community has the will to apply them.

Cambodia is not asking the world for pity. It is asking the world to believe what the evidence already shows: A powerful neighbour chose escalation. Cambodian civilians paid the price.
And international law must answer.

Footnote

Contact