Are tensions between Thailand and Cambodia heating up or simmering down? My guess is the latter – for now, at least. The situation peaked on May 28 when a Cambodian soldier was shot dead by Thai troops in the contested Mom Bei area close to the border with Laos. Strong words followed. On June 6, Bangkok ordered its army to close or restrict access at several border checkpoints, disrupting cross-border trade. Yet just days later, Phnom Penh agreed to withdraw its troops to positions held last year.
Phnom Penh still says it wants to take the matter to the International Court of Justice (ICJ), which previously ruled in Cambodia’s favor in 1962 and again in 2013 over another border dispute with Thailand. On June 10, it announced the formation of a committee, chaired by Foreign Minister Prak Sokhonn, to prepare documentation for a potential case. Bangkok responded by further tightening border crossing restrictions.
The Thai government firmly opposes ICJ arbitration, insisting that the matter be resolved through bilateral discussions, a position Bangkok is being pressured into taking by hard-line nationalists trying to shake Prime Minister Paetongtarn Shinawatra’s weak coalition government. The first of these talks is due on June 14, at a meeting of the Joint Boundary Committee, established in 2000 to handle such disputes.
So, where do things stand? Since Thailand strongly opposes allowing an international court to weigh in on matters of its sovereignty, it’s highly unlikely Bangkok would agree to co-submit a case to the ICJ. Cambodia could file unilaterally, but that would be a risky move.
The international context matters. Despite being Cambodia’s “ironclad friend,” China has taken a neutral stance and has only offered to mediate between Bangkok and Phnom Penh. The United States has said almost nothing about the border flare-up. U.S.-Thai relations are far better than U.S.-Cambodia ties, and one imagines Washington would side with Bangkok if push came to shove. Some Southeast Asian and European envoys have urged both capitals to bring the matter to the Association of Southeast Asian Nations (ASEAN), but neither government seems to have seriously considered this, and Malaysia, this year’s ASEAN chair, has shown little interest in pushing for regional mediation efforts.
We’re not in a golden age of international law, and even a favorable ICJ ruling would leave Phnom Penh in a bind. Would foreign governments step in to enforce a decision? Beijing has spent years ignoring the Permanent Court of Arbitration’s 2016 ruling favoring the Philippines in their South China Sea disputes. The U.S. under Donald Trump is dismissing international law outright and has even sanctioned the International Criminal Court. ASEAN, for its part, always opts for neutrality, treating the 2016 arbitration award as a bilateral matter between Beijing and Manila, for instance.
According to Prime Minister Hun Manet, an ICJ ruling would “end this problem and extinguish it once and for all so that there is no further confusion.” Not really. What if the ICJ sides with Cambodia but Thailand refuses to accept the ruling, which it almost certainly would if Phnom Penh acts unilaterally? Would Cambodia then attempt to control the territory by force? Or back down in embarrassment? Recall that the ICJ ruled in Cambodia’s favor over the Preah Vihear temple in 1962, but that didn’t stop both sides from engaging in deadly clashes in 2008. The only way ICJ arbitration works for Cambodia is if Thailand agrees, which seems unlikely, or if Phnom Penh can secure commitments in advance from key powers – namely China and ASEAN – to pressure Bangkok to accept the ruling. But that also seems a long shot.
That leaves bilateral dialogue, Bangkok’s preferred option. My guess is that Cambodia sees this as the most likely outcome too, although it’s sensibly laying the groundwork for a parallel strategy. Preparing an ICJ case gives it leverage heading into bilateral talks. Without the ICJ threat, Thailand holds the much stronger hand: it’s economically and militarily more powerful, can restrict trade, and could go so far as to expel hundreds of thousands of Cambodian migrant workers, an economic blow Phnom Penh surely wants to avoid.
The ICJ option, then, gives Cambodia a bargaining chip if Bangkok approaches the talks too aggressively. In other words, Cambodia has an alternative that Bangkok would not want it to pursue. Moreover, the threat of taking the case to the ICJ allows Cambodia to garner some international support. After all, it could say, “we’ll try Bangkok’s preferred path of bilateral talks, but if Thailand isn’t willing to negotiate honestly and fairly, then we’ll refuse to be bullied and will submit our case to the will of international law.”
The ruling Cambodian People’s Party now seems focused on controlling the narrative and ensuring that conciliation doesn’t appear weak. Hun Sen, the former prime minister – and Hun Manet’s father – still calls the shots behind the scenes and has recently sought to cool tensions. Things had been heating up: tycoons were calling for boycotts of Thai goods, and some academic institutions suspended joint projects with Thai universities.
Incidentally, this saga has been politically useful. Since 1979, the CPP has struggled to dominate Cambodia’s nationalist discourse. Strident anti-Vietnamese nationalism has long been the domain of opposition parties, notably the now-banned Cambodia National Rescue Party, which nearly won the 2013 general election on that wave. The CPP, by contrast, has pushed an “inclusive” nationalism centered on peace and prosperity.
Early last year, the party failed to manage nationalist outrage over the relatively obscure Cambodia–Laos–Vietnam Development Triangle Area agreement, which some Cambodians suddenly started to see as a threat to national sovereignty. The government tried to repress protests by claiming they were fomenting a “color revolution.” In the end, it capitulated and withdrew from the agreement in September.
However, the CPP dipped its toes into anti-Vietnamese rhetoric last year for the first time, in response to criticism of the planned Funan Techo Canal project. After Vietnamese academics and public figures (though not Hanoi itself) voiced concerns over the megaproject’s environmental and geopolitical implications, Hun Sen and Hun Manet framed it as a nationalist imperative, a means of breaking free from Vietnamese control over Cambodia’s trade (the canal would mean that most Cambodian imports and exports would no longer need to go through Vietnamese ports) and something Cambodia would pursue regardless of opposition from the CPP’s longtime ally. Hun Manet called the project essentially for “the Kingdom’s independence,” presumably from Vietnam. As Hun Sen put it, “Cambodia is not more inferior than Vietnam…Cambodia knows how to protect its interests; Vietnam does not need to care.”
Now, the tensions with Thailand have offered the CPP another opportunity to burnish its “jingoistic” credentials. Hun Manet, previously the army chief, has played the part of a militarist leader. The Hun family and other top officials have visited troops near the border and engaged in patriotic pageantry. What will be interesting – and novel – is whether the CPP can successfully whip up nationalist fervor, as it has, and then dial it back. Since 2017, it has consolidated control over politics, the economy, media, and the middle class. If it can now dominate both “inclusive” and “jingoistic” nationalism, it would further entrench its authority.