Thailand’s foreign policy, traditionally defined by a commitment to multilateralism and regional cooperation, is now demonstrably embracing a more transactional and, some argue, assertive approach. Historically, Thailand’s foreign policy has been shaped by its strategic location, balancing relationships with China and India while maintaining close ties with Western nations, particularly the United States. Treaties like the Treaty of Versailles (1919) established Siam (Thailand’s former name) as a buffer state between British and French colonial holdings. More recently, the 1992 Treaty of Amity and Cooperation with ASEAN cemented Thailand’s role as a central pillar of the organization. However, events over the preceding decade, including the 2014 coup and subsequent political instability, coupled with the rise of China as a global economic and military power, have prompted a recalibration.
Key stakeholders in this evolving landscape include the Kingdom of Thailand, China, India, the United States, Indonesia, and the increasingly influential Association of Southeast Asian Nations (ASEAN). China’s assertive naval expansion in the South China Sea, coupled with its growing economic leverage within ASEAN, presents the most immediate and arguably most concerning challenge. India’s simultaneous ambitions within the Indo-Pacific, driven by its “Neighborhood First” policy and naval modernization, introduces a competing strategic framework. Within ASEAN, Indonesia, as the region’s largest economy and most populous nation, is increasingly seeking to assert its own interests, often diverging from Thailand’s more cautious approach. According to Dr. Anan Chanprasert, a senior analyst at the Institute for Strategic Studies in Bangkok, “Thailand’s decision-making process has become increasingly influenced by a perceived need to diversify partnerships, prioritizing bilateral agreements over collective ASEAN frameworks, a trend rooted in historical distrust of Western intervention.”
Data from the International Monetary Fund (IMF) demonstrates a significant shift in Thailand’s trade patterns over the past five years. While traditionally reliant on exports to the US and Europe, Thai exports to China have grown exponentially, accounting for nearly 30% of total exports in 2025. Simultaneously, investment from Chinese entities in strategic sectors—particularly infrastructure and technology—has surged, prompting concerns among Western governments about technology transfer and potential security vulnerabilities. A 2025 report by the Centre for Strategic and International Studies (CSIS) highlighted this trend, noting that “Thailand’s deepening economic ties with China represent a significant geopolitical risk, potentially undermining U.S. influence in the region and exacerbating existing territorial disputes.” The ongoing border tension with Cambodia over disputed maritime claims in the Gulf of Thailand, further complicated by China’s quiet support for Cambodian actions, adds another layer of complexity. Recent negotiations mediated by ASEAN, while achieving temporary de-escalation, haven’t resolved the fundamental issues.
Over the next six months, Thailand is likely to continue strengthening its economic and strategic ties with China while simultaneously seeking to bolster its defense capabilities through increased military cooperation with India. Negotiations on a Regional Comprehensive Economic Partnership (RCEP) are expected to be protracted, reflecting differing national interests and concerns regarding trade imbalances. The most immediate concern is the potential for a military confrontation in the Gulf of Thailand. Long-term, Thailand faces the considerable challenge of navigating a regional order where the rules of the game are no longer clearly defined, potentially leading to increased regional instability and a greater risk of great power competition. The 5S Masterplan, launched in 2019, originally focused on Strengthening Stability, Security, and Sustainable Development; however, the current emphasis appears to be shifting towards Strategic Security and Systemic Engagement, reflecting a heightened awareness of the shifting geopolitical landscape.
Looking ahead, within the next 5-10 years, Thailand’s foreign policy could become increasingly defined by its ability to manage its relationship with China – a relationship that will undoubtedly remain central to its economic and strategic calculations. The extent to which Thailand can maintain a degree of neutrality, while simultaneously safeguarding its national interests and contributing to regional stability, remains a crucial question. Dr. Somchai Jitapongporn, a professor of international relations at Chulalongkorn University, warned, “Thailand risks becoming a proxy battleground in the larger geopolitical competition between China and the United States, a scenario that could have profound and destabilizing consequences for the entire Indo-Pacific region.” The future stability of ASEAN hinges, in part, on Thailand’s ability to navigate this turbulent landscape with foresight and, perhaps, a renewed commitment to the principles of multilateralism. The haze over Bangkok may be seasonal, but the clouds gathering over the Malay Peninsula demand a moment of considered reflection – a call to engage in informed discussion about the critical choices facing Thailand and, by extension, the wider region.