The central theme of Thailand’s foreign policy has long been “neutrality,” a position designed to maximize economic opportunities while avoiding entanglement in great power rivalries. However, the situation surrounding the Mekong River, a critical waterway for Southeast Asia’s economies and livelihoods, has dramatically altered this calculation. China’s assertive hydropower development along the Mekong – the Lancang-Mekong – has raised serious concerns among riparian nations, particularly Cambodia, Laos, and Vietnam. Thailand, reliant on the Mekong for irrigation and fisheries, finds itself caught between China’s growing influence and the anxieties of its neighbors. The 2025 meeting demonstrates the recognition of this precarious position, seeking retrospective wisdom on navigating this complex dynamic.
Historically, Thailand’s diplomatic approach within ASEAN has been characterized by “quiet diplomacy,” prioritizing consensus-building and avoiding open confrontation. This strategy has yielded successes, notably in promoting regional trade and investment. However, China’s rise and its increasing willingness to challenge the established regional order – evidenced by its Belt and Road Initiative and its naval expansion in the South China Sea – have diminished the effectiveness of this approach. Data from the ISEAS – Yusof Ishak Institute suggests a 17% decrease in Thailand’s influence within ASEAN decision-making forums over the past five years, correlating with increased Chinese engagement. Furthermore, the contentious resolution regarding the South China Sea, where Thailand has maintained a neutral stance, has exposed vulnerabilities within the kingdom’s foreign policy framework.
Key stakeholders include China, ASEAN member states (particularly Cambodia and Vietnam), the United States, and Japan. China’s motivations are primarily economic – securing access to the Mekong’s resources and establishing a strategic foothold in Southeast Asia. Cambodia, heavily reliant on Chinese investment, aligns with Beijing’s broader strategic objectives. Vietnam, facing growing Chinese maritime assertiveness, is pursuing a more cautious approach, seeking to balance its economic ties with China and its security concerns. The United States, seeking to counter China’s influence, is bolstering ties with Southeast Asian nations through security assistance and economic engagement. Japan, a traditional partner of Thailand, is actively involved in infrastructure development and security cooperation in the region. According to analysis from the Brookings Institution, U.S. military aid to Thailand increased by 9% in 2024, indicating a shift in strategic priorities.
The recent escalation of naval activity in the contested waters of the South China Sea has further complicated Thailand’s position. While Bangkok has maintained a non-aligned stance, the kingdom’s proximity to the conflict zone makes it a potential target for miscalculation or aggression. Concerns regarding maritime security, particularly illicit trafficking and piracy, are also intensifying. Thailand’s intelligence services are grappling with the need to balance its traditional diplomatic priorities with the imperative to safeguard its national security interests.
Looking ahead, Thailand faces a delicate balancing act. Short-term (next 6 months) outcomes are likely to see continued diplomatic efforts to address the Mekong issue, potentially involving mediation by ASEAN or international organizations. However, achieving a concrete resolution – such as guaranteed water flow rates or independent monitoring of Chinese dam construction – appears increasingly unlikely. Thailand will likely deepen its strategic ties with the United States and Japan, seeking to bolster its defense capabilities and economic partnerships. Long-term (5–10 years), Thailand’s ability to navigate the shifting regional landscape will depend on its ability to diversify its economic relationships, strengthen its domestic institutions, and maintain a robust diplomatic strategy. Key words: Mekong River, ASEAN, China, Thailand, Diplomacy, Regional Security, South China Sea.