1904 Treaty Evidence Sparks Thai Bid to Reclaim Preah Vihear Temple

Freelance historian Thepmontree Limpayom has called on Prime Minister Srettha Thavisin’s cabinet to reopen the debate over Preah Vihear, arguing that 'new evidence' hidden in the 1904 Franco–Siamese Treaty overturns past interpretations of the border. The 1962 ICJ decision awarded sovereignty of Preah Vihear to Cambodia—a ruling Thailand accepted under a UN reservation lodged immediately after the judgment. He claims that Cambodia’s own documentation recognizes the watershed ridge at the cliff’s edge as the dividing line, placing the centuries-old temple within Thai territory.

Diplomatic Toolbox Reopened

Since the International Court of Justice (ICJ) handed down its 1962 verdict, Thailand has operated under a formal 1962 UN reservation, lodged with the Secretary-General immediately after the ruling. Thepmontree proposes that Bangkok pass a Cabinet resolution instructing the Ministry of Foreign Affairs to notify the UN that Thailand no longer accepts the ICJ decision. This step, he argues, would reassert Thailand’s right to pursue legal avenues for sovereignty claims.

Geography vs Colonial Cartography

The heart of the dispute lies in contrasting readings of colonial-era maps and natural topography. Under Article 3 of the 1904 treaty, the international boundary follows the mountain’s watershed. French surveyors in 1907 produced Annex I maps that placed Preah Vihear on Cambodia’s side, but Thepmontree insists these charts ignored LiDAR-based topographic surveys and Cambodia’s own World Heritage management plans, which align the watershed with the temple’s cliff.

Marching Orders?

More controversially, the historian does not rule out a security deployment. He envisions the Royal Thai Army’s Second Army Area establishing a base at Preah Vihear to 'protect' Thai sovereignty. While his proposal cites the 1904 convention as legal cover, critics warn any troop movements risk igniting border skirmishes and drawing international condemnation under UNESCO’s 1972 heritage convention.

Neighbors on Alert

In Phnom Penh, authorities have denounced any suggestion of reversal as an attack on World Heritage integrity, calling on UNESCO and ASEAN to intervene. Within Thailand, analysts caution that a hardline approach could strain relations with ASEAN partners and derail ongoing cultural and environmental collaborations along the Phanom Dong Rak range.

Looking Forward: Implications for Thailand

Whether the government will embrace or dismiss Thepmontree’s blueprint remains to be seen. For Thais living near the border, the debate could mean:

• Increased military and police presence

• Fluctuating cross-border tourism flows

• Heightened diplomatic tensions in ASEAN

As Bangkok weighs historical grievances against modern regional stability, the fate of Preah Vihear may redefine how Thailand balances national pride, legal tradition, and international cooperation in the years ahead.