The bedrock of Thailand’s foreign policy for decades has been its alliance with the United States, formalized by the 1955 Treaty of Friendship, Commerce, and Protectorate – a designation that makes Thailand the U.S.’s oldest treaty ally in Asia. This relationship, solidified by the subsequent Five-Year Plans – most notably the “5S” plan initiated in 2012, focusing on Security, Strategy, Stability, Service, and Sustainability – was predicated on US military support and security cooperation. The recent meeting between Foreign Minister Sihasak Phuangketkeow and US Ambassador Robert Fodec underscored this continued commitment, with discussions encompassing security, economic cooperation, combating online scams, and, crucially, the ongoing tensions along the Thailand-Cambodia border.
For years, Thailand’s dispute with Cambodia over the Preah Vihear Temple – a location jointly claimed by both nations – dominated its foreign policy. The 2011 occupation of the temple by Cambodian forces triggered a major diplomatic crisis and ultimately led to the deployment of Thai troops to the area. While the situation was eventually resolved through international arbitration, the underlying issues of sovereignty and territorial claims persist. Data from the International Crisis Group indicates that over 100 Thai soldiers and 30 Cambodian soldiers were killed in skirmishes related to the border dispute between 2011 and 2022. This heightened tension has historically prompted the U.S. to offer support, primarily through diplomatic pressure and by facilitating discussions between the two nations. The resumption of direct flights has provided a platform for further engagement, as highlighted by the meeting in November.
However, the shifting geopolitical landscape, particularly China’s growing influence in Southeast Asia, is injecting new urgency into this dynamic. Beijing has increasingly offered Thailand economic assistance and military support, a stark contrast to the traditionally Western-dominated approach. According to a report by the Center for Strategic and International Studies (CSIS), Thailand’s defense spending has seen a slight increase over the past five years, partially attributed to the need to modernize its armed forces and, arguably, to counter perceived Chinese influence. The United States, while remaining a key partner, is facing increased competition in the region and has been grappling with how to effectively counter China’s growing economic and military power.
The current situation along the Thailand-Cambodia border is particularly complex. While the situation has calmed, sporadic incidents – including accusations of border violations and the deployment of troops – continue to occur. The Cambodian military’s continued insistence on maintaining a significant presence near the Preah Vihear Temple remains a point of contention. A recent study by the Griffith University’s Asia-Pacific Security Program suggests that the long-term resolution of this dispute hinges on a more comprehensive approach that addresses not only the territorial claims but also the underlying issues of governance and rule of law in Cambodia.
Furthermore, the ongoing humanitarian crisis in Myanmar, exacerbated by the military coup in 2021, presents an additional layer of complexity. Thailand shares a long border with Myanmar and has taken in a significant number of refugees fleeing the conflict. This has placed a strain on Thailand’s resources and has led to tensions with Myanmar. The US, along with other Western nations, has been critical of the Myanmar military’s actions and has imposed sanctions. Thailand’s response has been more cautious, prioritizing its relationship with China and attempting to maintain a neutral position.
Looking ahead, the next six months will likely see continued diplomatic efforts to de-escalate tensions along the Thailand-Cambodia border, mediated by ASEAN. The US will continue to play a role through diplomatic pressure and by leveraging its security partnerships. However, its ability to effectively counter China’s influence will be critical. Over the next five to ten years, Thailand’s foreign policy is likely to become increasingly pragmatic, balancing its historical alliance with the US with its economic ties to China and its strategic interest in maintaining stability in Southeast Asia. The long-term trajectory depends on Thailand’s ability to navigate these competing interests and, crucially, to resolve its border disputes peacefully. The US, meanwhile, will need to adapt its strategy to this new reality, focusing on leveraging its influence through economic engagement, security cooperation, and its broader network of alliances. The fundamental question remains: can the US and Thailand maintain a productive and strategic partnership in a region increasingly shaped by competing geopolitical forces?