Thailand–Cambodia Border Crisis | ASEAN Mediation Push

The issue reached the International Court of Justice (ICJ) in 1962, when the court ruled by 9 votes to 3 that sovereignty over the Preah Vihear temple itself belonged to Cambodia, largely because Thailand had accepted the 1907 map for decades without formal protest. Importantly, however, the judgment did not definitively demarcate the surrounding land, leaving a residual zone of ambiguity around the temple precincts.

That unresolved perimeter became a recurring flashpoint. After Cambodia succeeded in having Preah Vihear listed as a UNESCO World Heritage Site in 2008, nationalist backlash in Thailand triggered armed skirmishes that killed dozens between 2008 and 2011. Cambodia again approached the ICJ, which issued a clarifying interpretation in 2013, affirming that Thailand must withdraw military forces from the temple’s “vicinity” and respect Cambodia’s sovereignty over the promontory on which the temple stands. While the 2013 ruling significantly reduced tensions for over a decade, it still stopped short of a comprehensive border settlement, effectively freezing—but not resolving—the dispute.

In the current cycle, Cambodia says the crisis sharpened again earlier this year, and the most recent flashpoint came after a border skirmish on 7 December, with clashes resuming from 8 December across multiple points along the roughly 817-km border—from inland areas near Laos to coastal provinces—using tanks, artillery and drones, and with Thailand conducting airstrikes.

This is not the first attempted de-escalation in 2025. A short-lived July ceasefire was brokered with external involvement, and a subsequent October joint declaration in Kuala Lumpur reaffirmed commitments to peaceful settlement and restraint—yet both sides later accused the other of violations and the arrangements unraveled. In recent weeks, the conflict has also spilled into economic-pressure measures: Thailand halted some fuel shipments via a Laos crossing citing fears of diversion amid the conflict. Alongside ASEAN’s push, both the United States and China have pursued separate diplomatic efforts, but without a sustained halt to hostilities.

Why this matters:

Beyond the immediate humanitarian emergency—mass displacement, risks from unexploded ordnance/landmines, and allegations of strikes affecting civilians—the crisis is a direct test of ASEAN’s credibility as a regional security manager. A workable ceasefire here will likely depend on sequencing (who stops first), verification (including monitoring mechanisms now being discussed), and whether both capitals can accept “face-saving” terms that prevent the next flare-up from becoming a prolonged, militarised stalemate.