Thailand and Cambodia agreed to an unconditional ceasefire on 28 July, following a five-day border conflict. Taking effect at midnight the following day, the ceasefire had been agreed upon by Cambodian Prime Minister Hun Manet and Thai acting Prime Minister Phumtham Wechayachai at a specially convened summit held in and facilitated by Malaysia. While Thailand initially rejected third-party mediation, threats by US President Donald Trump to call off trade talks with both countries seemingly pushed both leaders to eventually meet and work out a ceasefire.

The five days of fighting that erupted on 24 July were the most violent border clashes between both states in more than a decade, with some 43 people killed, hundreds injured, and 300,000 civilians displaced. Most media narratives attribute the roots of the conflict to a decades-long border dispute between Thailand and Cambodia, particularly over several Angkorian-era temples straddling the border. Among the most prominent of these are the 1,000-year old Hindu temples of Preah Vihear and Prasat Ta Muen Thom.

At the heart of the dispute are maps drawn up following a series of treaties signed between the French (who controlled Cambodia at the time) and Siam (now Thailand, and never colonised) in the early 1900s. These maps established the modern borders of Thailand and Cambodia while leaving considerable stretches un-demarcated, setting the stage for future disputes.

Between 2008 and 2011, heightened tensions over the Preah Vihear temple saw intermittent fighting take place between both countries, killing more than 20 people and internally displacing thousands more.

That being said, to reduce the recent fighting to a border dispute doesn’t explain the escalation to artillery bombardments and air strikes last month. To understand the deeper roots, we must look at the breakdown in relations between both countries’ respective ruling political dynasties, namely the Shinawatras of Thailand and the Huns of Cambodia. Both are led by two former premiers of each country – business tycoon Thaksin Shinawatra of Thailand and strongman Hun Sen of Cambodia. Once referring to each other as ‘god brothers’, the dramatic falling out between both men helped exacerbate border tensions between both countries.

For decades, Cambodia has been under the iron-fisted rule of the Hun dynasty, established under its patriarch Hun Sen. Formerly a middle-ranking officer under the Khmer Rouge, Hun Sen defected to Vietnam and established himself under the new regime installed by the Vietnamese after their invasion and occupation of the country in 1979. In 1985, Hun Sen rose to the position of prime minister, and would, over time, proceed to establish a personalist dictatorship.

The Hun Sen regime has imprisoned opposition leaders and driven others into exile, while also clamping down on independent media and civil society. In 2017, Cambodia’s Supreme Court dissolved the main opposition, the Cambodian National Rescue Party, over allegations of conspiring with foreign powers. In 2023, Hun Sen would resign and hand over power to his son Hun Manet. Despite this, many have suggested that Hun Sen remains firmly in charge.

In neighbouring Thailand, politics for the last 25 years has been dominated by the Shinawatra dynasty, established by telecoms tycoon Thaksin Shinawatra, who was elected to power in 2001 and 2005. Thaksin would secure a devoted following among rural and lower-middle class Thais through his populist policies of ‘Thaksinomics’, which included universal healthcare and debt moratoriums for farmers. Yet Thaksin was also accused of cronyism, of co-opting bureaucrats and regulators to benefit his business empire.

The Shinawatras’ electoral clout ultimately made them a threat to Thailand’s conservative establishment, centred around the institutions of the military and the monarchy. Thaksin was ousted in a military coup in 2006 and went into exile in 2008 to escape corruption charges. Since then, Thai politics has seen a constant power struggle between the Shinawatras and the conservative establishment. Several Shinawatras and their allies have held the position of prime minister, only to be ousted through judicial interventions and military coups.

Until recently, the Thai government had been led by Thaksin’s daughter Paetongtarn. Her premiership had been the result of an uneasy alliance made between the Shinawatras’ Pheu Thai party and several smaller pro-military parties to form a government in the aftermath of the May 2023 general election.

On the same day that Pheu Thai took power, Thaksin returned to Thailand after nearly 15 years in self-exile and despite being convicted of corruption charges. Upon arrival, he had been immediately arrested and sentenced to imprisonment, but was subsequently transferred to a police hospital hours later due to supposed health issues. He was granted parole in February 2024, having spent almost no time in a prison cell. This prompted speculation that Thaksin’s return had been the result of a bargain made between the Shinawatras and Thailand’s conservative establishment. Upon being released, Thaksin has been accused of meddling in politics from behind the scenes, with Paetongtarn being seen as nothing more than a proxy for her father.

With the return of the Shinawatras to power, one would be forgiven for thinking that friendlier ties between Thailand and Cambodia were on the horizon. Indeed, the Shinawatras and the Huns enjoyed a close relationship going back decades. After his ousting in 2006, Thaksin had taken refuge in Hun Sen’s Cambodia, as did Thaksin’s sister and former prime minister Yingluck Shinawatra after a coup in 2014. In 2009, Hun Sen had appointed Thaksin as an economic adviser. Upon Thaksin’s return to Thailand from exile, Hun Sen was the first foreign dignitary to visit him.

What followed instead were renewed border tensions. These started on 13 February when Cambodian troops and civilians climbed onto the ruins of Prasat Ta Muen Thom and sang a patriotic song, sparking a diplomatic incident with Thailand. This incident prompted military mobilisation on both sides. Tensions escalated further on 28 May after an exchange of fire saw one Cambodian soldier killed.

Things escalated much further on 18 June, when Hun Sen leaked a phone call between him and Paetongtarn which had taken place three days prior, during which the two discussed the border tensions. During the phone call, Paetongtarn took an overly deferential tone with regards to Hun Sen, describing him as ‘uncle’ and offering to take care of ‘anything he wants’ in order to reduce border tensions. More damagingly, she accused the Thai army of being aligned against her government.

This phone leak sparked public outrage in Thailand, leading to the withdrawal of a major party from Paetongtarn’s coalition. On 1 July Thailand’s Constitutional Court suspended Paetongtarn from office pending an ethics investigation. During all this, Hun Sen threatened to make further damaging revelations against Thaksin, including supposed insults directed towards the Thai monarchy.

Tensions would peak in July after two landmine incidents injured Thai soldiers. Bangkok responded by expelling the Cambodian ambassador and recalling their own from Phnom Penh. Fighting would break out on 24 July near Ta Muen Thom temple, with both sides claiming they had acted in self-defence.

As the fighting raged, Thaksin and Hun Sen lobbed accusations against each other. Hun Sen claimed that Thaksin had initiated the conflict ‘under the pretext of taking revenge on Hun Sen’. Thaksin, for his part, called upon the Thai military to ‘teach that wily Hun Sen a lesson’.

Evidently, the friendly ties between the Shinawatras and the Huns have all but evaporated, with Hun Sen determined to take the Shinawatras down. According to satellite analysis conducted by the Australian Strategic Policy Institute, in the months leading up to the conflict Cambodia arguably contributed more to escalating border tensions, with the analysis finding ‘33 escalatory events attributed to Cambodia, compared with 14 attributed to Thailand, alongside nine joint de-escalatory efforts’.

What sparked this rift? Some have suggested that Thailand’s recent moves to crack down on transnational cyber-scam operations threatened a lucrative source of revenue for Cambodia. Often operated by Chinese gangs, these industrial-scale operations frequently rely on trafficked victims to carry out the scams. According to the US Institute of Peace, Cambodia’s scam centres generate as much as US$12.5 billion annually, roughly half of the country’s GDP. Bolstering this theory is the fact that the Thai military deliberately targeted a scam compound during the fighting. Hun Sen may also be reacting to recent moves by Thailand to legalise gambling, which would have threatened Cambodia’s lucrative gaming profits.

With the dust beginning to settle along the border, all eyes are now on the future of the now vulnerable Shinawatras in Thailand. While Paetongtarn awaits the Constitutional Court’s verdict, Thaksin himself faces several legal woes, including a court inquiry into the legality of his controversial hospital stay during his prison sentence, as well as (more seriously) old lèse-majesté charges. Amid the political manoeuvering currently taking place to form a new government, concerns have been raised about Thailand’s military launching another coup.

Ultimately, the five days of fighting between Thailand and Cambodia revolve around more than just disputes over vague French maps and the ownership of ancient temples. A dramatic falling out between two of Southeast Asia’s most powerful families would trigger some of the worst inter-state fighting the region has seen in decades. Whether this rift will heal will play a large part in determining the future of Thai-Cambodian relations.