Why did Thailand and Cambodia fight a senseless border war?

Much of the disputed border area between Cambodia and Thailand is dotted with Hindu temples built on steep cliffs nearly 1,000 years ago. On the morning of July 24th the sound of gunfire echoed through the ancient ruins.

It is not clear who shot first. But by noon Cambodian and Thai soldiers were attacking each other at eight spots along a 200km frontier. Cambodia’s army launched rockets at Thailand, and a Thai F-16 fighter jet dropped bombs inside Cambodia. Not since the Cambodian civil war ended more than three decades ago have these highlands seen such shocking violence. After five days of war more than 40 are dead, hundreds injured and 300,000 civilians displaced.

The two sides’ prime ministers agreed to a ceasefire at a hastily convened summit in Kuala Lumpur, Malaysia’s capital, on July 28th. Anwar Ibrahim, the prime minister of Malaysia, which currently chairs the Association of South-East Asian Nations (ASEAN), facilitated the negotiations. But diplomats from several countries pointed to America as the talks’ key mover. A threat by President Donald Trump to halt trade negotiations with both Cambodia and Thailand until a truce had been reached forced both sides to the negotiating table.

Even so, the ceasefire looks shaky. Thai diplomats acknowledge that the situation is now more peaceful, but also allege that Cambodian troops have repeatedly violated the agreement with grenades and small-arms fire. Cambodians deny this. Military commanders on both sides have met, and appear to be working towards peace. It is possible that the situation will continue to get better, but equally possible that a skirmish will ignite the conflict again.

To understand why, it helps to know the history. The dispute dates back to a 1904 treaty signed between the kingdom of Siam and colonial France, which had conquered much of what is now Vietnam, Laos and Cambodia. The two agreed to define their border as the natural watershed in the area, known as the Dangrek mountains. Four years later, however, France’s map-makers drew a line that put high ground and several historically important temples on its side of the border instead. The International Court of Justice awarded the largest of the temples to Cambodia in 1962, citing the French map. Thai diplomats have been smarting about the quality of French cartography ever since.

The two countries have tried to clear things up diplomatically, especially since the surrender of the last remnants of the Khmers Rouges in the area in 1999. But nationalism on both sides has got in the way. Cambodians feel a deep emotional attachment to temples built by the Khmer empire, which they claim as their heritage. For their part, Thais say the temples were part of Siam until European colonialists arrived in the 19th century. In 2008 this became open conflict when Thai protesters broke into the largest of the temples, Preah Vihear. Three years of skirmishes left 34 dead. Things quietened down again following a second ruling by the International Court of Justice in The Hague.

Why is the fighting flaring up again now? Both sides say the other’s politics is driving it to make aggressive moves. Thais say Cambodian troops occupied one of the temples in February only after Thailand launched a crackdown on the scam industry, which thrives along its border with Cambodia. They suggest that Cambodia’s still-powerful former leader, Hun Sen, may have been angered by this crackdown. Analysts estimate that revenues from scams now account for a large share of the Cambodian economy. Thais also speculate that Mr Hun Sen is unhappy with the slow pace of negotiations to resolve overlapping claims to oil and gas deposits in the Gulf of Thailand that could provide a windfall for poorer Cambodia.

Cambodian officials and analysts reject these theories. Mr Hun Sen, they say, is not so dependent on revenues from the scam compounds or oil- and gasfields as the Thais suggest. They point the finger instead at Thai generals, who they say are using the conflict to whip up nationalist sentiment that might make it easier for them to mount a coup at home. Thailand’s generals have form in this regard: they have launched a dozen successful coups since Thailand’s absolute monarchy ended in 1932. The last two came against members of the Shinawatra clan, which is in power again at the moment.

Whether it has been the armed forces’ goal or not, Thai politics has indeed been destabilised by the dispute. A recording of a conversation between Paetongtarn Shinawatra, the prime minister, and Mr Hun Sen regarding the border was leaked in June. In it, she criticises the Thai army commander-in-charge of the area and calls Mr Hun Sen “uncle”, a term of endearment in Asia. As a result, senators aligned with her opponents petitioned the constitutional court to remove her from office. On July 1st she was suspended while the court considers the case.

In the meantime, one of Ms Paetongtarn’s deputies, Phumtham Wechayachai, is leading a government that holds a razor-thin majority in parliament. It seems unlikely that it will last the year. As the Shinawatras dare not look weak following the phone call, they have backed the army to the hilt in the border war—undermining Cambodian theories about its origins.

None of these factors can fully explain the rapid escalation of the conflict in late July, however. Other analysts suggest that ego, too, may have played a role. Ms Paetongtarn’s father, Thaksin Shinawatra, was once fast friends with Mr Hun Sen. During his years in self-exile, the Thai tycoon would often visit his former counterpart, much to the annoyance of the army generals in Bangkok. But the two men appear to have suffered a falling-out earlier this year for reasons that remain obscure. Mr Hun Sen is known for his temper. Could a spoiled friendship have caused so much hardship for their peoples?

These unanswered questions and conspiracy theories make foreign diplomats in each capital nervous that the ceasefire reached in Malaysia may not hold. Further political turmoil in Thailand is a certainty. So are Mr Hun Sen’s volatile moods. A return to hostilities is not in the interests of either nation. But the opacity of decision-making on each side puts the other on full alert. A more democratic political system in both countries, or at least one that offers greater transparency, would help ease tensions. Yet after a week of fighting, it looks an ever more unlikely prospect. ■