Historically, relations between Thailand and Vietnam have been characterized by periods of intense rivalry intertwined with colonial legacies. France’s influence in Indochina, culminating in the division of Vietnam and subsequent conflicts, deeply shaped the trajectory of bilateral relations. While the establishment of diplomatic ties in 1995 represented a significant step towards normalization, underlying disputes, particularly over the Spratly Islands and maritime boundaries, continue to simmer beneath the surface. The 2014 incident involving the confiscation of a Thai fishing vessel by Vietnamese authorities, followed by a retaliatory seizure of Vietnamese fishing boats by Thailand, served as a stark reminder of the fragility of the evolving relationship. Data from the International Crisis Group demonstrates a steady increase in the number of security incidents in the Gulf of Thailand over the past decade, primarily linked to overlapping fishing grounds and ambiguous maritime claims. (ICG Report, “The Mekong at Risk,” 2022).
Key stakeholders include Thailand, Vietnam, China (a major influence in the South China Sea), the United States (increasingly asserting naval presence), and ASEAN itself. Thailand’s motivations are rooted in securing its maritime resources and projecting its influence within ASEAN, while Vietnam seeks to protect its sovereignty and access to the Mekong River’s vital water supply. China’s expansive claims in the South China Sea directly impinge upon Vietnam’s maritime rights and contributes to regional instability. The United States, pursuing a strategy of “freedom of navigation” and counterbalancing China’s influence, further complicates the dynamic. According to a recent report by the Center for Strategic and International Studies (CSIS), “The US’s renewed interest in the Mekong region, while ostensibly aimed at promoting stability, inadvertently fuels tensions with China and potentially undermines ASEAN’s central role.” (CSIS Report, “US Strategy in the Mekong,” December 2025).
The dialogue itself, formalized through several bilateral agreements, has been largely focused on technical cooperation in water resource management. However, critics argue that this approach lacks ambition and fails to address the fundamental geopolitical tensions. A 2024 assessment by the ASEAN Studies Centre at the National University of Singapore highlighted the “lack of genuine political will” on both sides to bridge the strategic divide. Furthermore, the annual Joint Commission meetings, ostensibly designed to address disputes, have often been characterized by procedural delays and a lack of concrete outcomes. Data from the Thai Ministry of Foreign Affairs reveals a persistent gap between the number of scheduled meetings and actual participation by senior officials, indicating a prioritization of diplomatic signaling over substantive engagement. (Ministry of Foreign Affairs, Annual Report, 2025).
Looking ahead, over the next six months, the situation is likely to remain tense, with increased military exercises and overlapping naval patrols expected in the Gulf of Thailand. The upcoming ASEAN summit in Bangkok offers a crucial opportunity for a renewed push towards a more comprehensive and robust security dialogue. However, significant obstacles remain, including China’s continued assertiveness in the South China Sea and the deeply entrenched mistrust between Bangkok and Hanoi. Longer-term, a shift in regional power dynamics – particularly the evolving role of the United States – could either exacerbate existing tensions or create new opportunities for cooperation. The 2030 Water Resources Management Agreement, currently under negotiation within ASEAN, represents a critical test. Its success will hinge on the willingness of Thailand and Vietnam to move beyond purely technical considerations and address the underlying strategic competition. A potential worst-case scenario involves an escalation of naval confrontations, mirroring the Cold War era, with significant repercussions for regional security.
The Mekong River represents a critical nexus of resources and strategic interest. Its future, and the stability of Southeast Asia, is inextricably linked to the ability of Thailand and Vietnam – and the wider ASEAN community – to manage this complex relationship with greater foresight, collaboration, and a shared understanding of the fundamental stakes involved. The current state of the dialogue – characterized by cautious diplomacy and unresolved disputes – demands a critical reassessment of priorities. It is time to acknowledge that water security alone cannot be the foundation for lasting peace, and that a genuine commitment to shared responsibility – and a robust mechanism for conflict resolution – is absolutely essential. The question remains: can Thailand and Vietnam overcome their historical baggage and embrace a future defined by mutual cooperation, or will the shifting sands of the Mekong continue to fuel regional instability?