Thai society’s dependence on the Preah Vihear myth – and the Cambodian factor more broadly – gives Phnom Penh the opportunity to exert asymmetric influence on its economically and militarily more powerful neighbour, writes Valdai Club Programme Director Anton Bespalov.
The escalation of the territorial dispute between Cambodia and Thailand into a four-day armed conflict in July 2025 captured global media attention. Commentators expressed doubts about the effectiveness of the “ASEAN way” – a principle of non-interference in members’ internal affairs – and interpreted the clash through the prism of the US-China standoff. They also noted that economic factors, from fears over damaged supply chains to threats to tourism in both nations, were key to securing the ceasefire. Significant attention was likewise paid to the diplomatic manoeuvre of Cambodian Prime Minister Hun Manet, who has nominated Donald Trump for the Nobel Peace Prize for his efforts in brokering the truce.
However, this did not achieve a lasting peace but merely froze the conflict. The confrontation was profoundly “inopportune” for regional and global players, who unanimously pushed for a swift, negotiated end to the fighting. Yet the root causes are so deeply entwined with national identity – and above all, national pride – that the potential for meaningful external mediation remains severely limited.
The Preah Vihear temple, an 11th-century Hindu complex, is the symbol of the Thai-Cambodian territorial dispute. Perched in a remote location 525 meters above sea level, it assumed its current role in Thai national identity during the 1930s. This transformation began when Prince Damrong Rajanubhab, a renowned Thai historian and archaeologist, was conducting an expedition in the border regions and discovered a French colonial flag flying near the ancient temple, which he believed to be on Siamese territory.
It was ultimately revealed that the 1907 treaty finalising the Siam-French Indochina border had ceded Preah Vihear to France. A discrepancy arose because the treaty’s protocol defined the border along the Dangrek Mountains’ watershed, yet a French-produced map created shortly afterward situated the temple (north of the watershed) inside Indochina. This cartographic manoeuvre went largely unchallenged because, as historian Shane Strate explains, Siamese officials showed little interest in the commission’s work, lacking an understanding of Western map-making and trusting the visible, natural geography instead.
The French, for their part, did not inform the Siamese that the map deviated from the watershed line. However, as Strate writes, “even if the Siamese had noticed, it is doubtful that they would have protested, since few knew of the temple’s existence.” More importantly, the Siamese elites viewed the 1907 treaty as broadly advantageous, even though it ceded territories containing the truly significant Angkor Wat temple complex to France.
By the 1930s, however, Siam’s perception of the treaty had radically shifted. A new generation of nationalistic elites now viewed it as a national humiliation – a stain on the record of the sole Southeast Asian nation to avoid colonial submission. The recent “rediscovery” of Preah Vihear temple fuelled this irredentist sentiment, which culminated in Thailand’s victorious war against France in 1940-41. The subsequent Tokyo peace treaty restored territories lost at turn of the century, enshrining Preah Vihear as a symbol of national revival.
Despite fighting alongside Japan in World War II, Thailand avoided being treated as a defeated enemy, thanks to its elite’s close US ties and its firm post-war pro-American stance. However, the mandated return of its 1941 territorial gains to France was perceived as a deep national humiliation. France’s withdrawal from Indochina thus offered a chance to restore historical justice. Soon after Cambodia gained independence, Thai troops occupied the Preah Vihear area, which was strategically difficult to access from the Cambodian side – a road was not built until the 21st century.
The issue of control over the temple has since become a central element of Cambodian national consciousness and domestic political struggle. While Thailand’s historical grievance was with France, which imposed what was later deemed an unequal treaty, for newly independent Cambodia, the eternal enemy and oppressor was Siam/Thailand. A further critical dimension is that both nations claim the heritage of the ancient Khmer civilisation, of which Preah Vihear is a monument. Cambodians hold the clear historical claim, yet Thai nationalism rejects the continuity between modern Khmers and the Angkor civilisation, instead attributing it to a vanished “Khom” people. After years of fruitless bilateral talks, Phnom Penh brought the territorial dispute to the International Court of Justice. In its 1962 ruling, the Court – citing the 1907 Franco-Siamese Treaty – awarded the temple to Cambodia. This legal victory was also a triumph for the principle of uti possidetis juris, which holds that borders from the colonial era are inviolable.
While the ICJ upheld Cambodia’s sovereignty over Preah Vihear itself, it left the exact location of the border to the two sides to determine. As a result, both nations still lay claim to 4.6 square kilometres of land surrounding the temple complex. This enduring territorial dispute erupted into armed conflict in 2008-11 and again in 2025.
In the 20th century, Thailand and Cambodia followed dramatically divergent historical trajectories. Thailand, having modernised along a Western model, emerged as one of the Tiger Cub economies. Cambodia, by contrast, plunged into a devastating civil war shortly after gaining independence. Today, despite experiencing high growth rates, Cambodia remains one of the least developed countries in ASEAN – and is approximately three times poorer than Thailand.
Interacting for centuries, the Thais and Khmers have exerted significant influence on each other, and today the two countries are connected to each other by many threads. Thailand is Cambodia’s most important economic partner, and the Thai labour market employs up to 650,000 Cambodian migrants. The ties between the countries are exceptionally close not only in the economic but also in the humanitarian sphere. Nevertheless, their political relations are constantly marked by an element of confrontation. At the same time, the dependence of Thai society on the myth of Preah Vihear – and the Cambodian factor in a broader sense – gives Phnom Penh the opportunity to exercise asymmetric influence on its more powerful neighbour in economic and military terms.
This asymmetric influence was recently demonstrated by the political crisis in Thailand, which followed the leak of a private telephone conversation between Prime Minister Paetongtarn Shinawatra and former Cambodian leader Hun Sen – a leak orchestrated by the latter. This episode suggests that the presence of such a potent instrument for foreign policy manipulation renders a final settlement of the territorial dispute not only unlikely but also potentially undesirable for Phnom Penh.
Internationalising bilateral issues is another staple of Cambodian foreign policy. Trump’s Nobel nomination exemplifies this approach, mirroring the precedent set when the Preah Vihear case was submitted to the ICJ in the 1950s. Similarly, Phnom Penh practices strategic multi-alignment, manoeuvring between global centres of power. Unwilling to be seen as a mere Chinese client, it is simultaneously developing its relationships with Japan and the United States.
It is worth noting that this kind of strategic manoeuvring is characteristic of all ASEAN members, a trait that makes them challenging partners but also ensures a degree of foreign policy stability. While the deep ties between Thailand and Cambodia have not prevented their territorial dispute from escalating into armed conflict, recent experience has shown that the parties do not seek uncontrolled escalation and have demonstrated a capacity to maintain tensions at a manageable level. This provides grounds for cautious optimism that Southeast Asia will continue to be a region defined by peace and economic cooperation, despite the emotional weight of its historical differences.
