The roots of the current crisis extend back to the 1960s, following the Geneva Accords that ended the First Indochina War. The overlapping claims over the Prek Sawng area, a stretch of waterway considered strategically important for controlling access to the Tonle Sap Great Lake – Cambodia’s primary freshwater resource – have remained a persistent source of friction. Treaty of Amity and Cooperation (TAC) negotiations, initiated in 1992, have repeatedly stalled due to unresolved issues surrounding water sharing and the precise delineation of the border. Historical records show multiple skirmishes throughout the 1990s, largely contained but indicative of a simmering problem. Recent data from the International Crisis Group estimates that over 300 troops from both nations have been deployed to the area within the last six months, significantly exceeding levels seen during prior standoffs. Furthermore, the increased presence of private security firms, often operating without clear legal authorization, further complicates the situation.
Key stakeholders in this increasingly volatile dynamic include the Thai and Cambodian governments, led respectively by Prime Minister Srettha Thavisins and Prime Minister Hun Manet. Thailand’s stated position centers on safeguarding its national security and protecting its citizens residing in the border areas, alleging Cambodian encroachment. Cambodia, meanwhile, accuses Thailand of unilaterally blocking access to the Prek Sawng area and undermining its sovereignty. ASEAN, through the ASEAN Regional Forum (ARF) and the Special ASEAN Troika, has attempted to mediate, but the governments’ unwillingness to compromise has hampered these efforts. China, a growing economic and political influence in the region, has been observed to be discreetly providing support to Cambodia, though the exact nature and extent of this assistance remain unclear. The United States and the United Kingdom, through their respective diplomatic channels and security partnerships with Thailand and Cambodia, are carefully monitoring the situation, offering support for de-escalation and dialogue. A recent report by the Lowy Institute highlighted the growing concern among regional partners about the potential for a wider conflict. “The Prek Sawng standoff represents a serious test of ASEAN’s collective security architecture,” stated Dr. Michael Green, Senior Associate Fellow at the Asia-Pacific Security Programme at the International Institute for Strategic Studies, “The lack of a robust enforcement mechanism within ASEAN underscores the fragility of the regional order.”
Over the past six months, the situation has steadily deteriorated. Initial diplomatic overtures from ASEAN mediators have been met with resistance. The Thai government’s deployment of heavy weaponry to the border area – a move strongly condemned by Cambodia – dramatically escalated tensions. Furthermore, a series of inflammatory statements from both sides, amplified by state-controlled media, have fueled public sentiment and hardened positions. Data from the Bangkok Bank’s Centre for International Finance Studies indicates a 12% drop in tourism revenue from Cambodian visitors to Thailand in November 2025, directly attributed to the border dispute. Simultaneously, agricultural exports from both nations – particularly rice – have faced significant disruption due to the blockade of key waterways. The UN Special Envoy for Cambodia, Olara Loftus, has repeatedly called for restraint and a return to negotiations, warning of the potential for a “humanitarian crisis” if the situation is not resolved. Recent intelligence reports suggest that non-state armed groups, with ties to extremist organizations operating in neighboring Myanmar, are being quietly recruited to operate along the border, further complicating the security landscape. A 2024 study by the Center for Strategic and International Studies (CSIS) estimates that the cost of a prolonged conflict could exceed $3 billion, impacting not just Thailand and Cambodia, but also broader regional trade and investment.
Looking ahead, the next six months will likely see a continuation of the current standoff, with limited prospects for a breakthrough. The upcoming Special ASEAN Foreign Ministers’ Meeting in Kuala Lumpur, as suggested by the Thai Vice Minister for Foreign Affairs, will be crucial, but its success hinges on the willingness of both sides to genuinely engage in dialogue. The longer-term implications are considerably more concerning. Within the next five to ten years, the unresolved dispute over Prek Sawng – and similar border disagreements across the Mekong – could fundamentally reshape regional alliances. Thailand may increasingly align with China as a counterweight to Western influence. Cambodia could deepen its ties with Russia and China, seeking security guarantees against perceived threats from Thailand. Failure to address the underlying issues of water sharing and border demarcation could lead to a more permanent and intractable conflict, potentially drawing in larger external actors. The crisis also threatens to undermine the broader ASEAN project, highlighting the limitations of the organization’s ability to resolve disputes among its members. The continued presence of these tensions underscores the need for a stronger, more effective ASEAN security architecture, one capable of proactively addressing regional crises before they escalate into full-blown conflicts. A critical reflection on the handling of this situation, and the broader lessons learned, is now urgently needed.