BANGKOK — Thailand’s long-standing security alliance with the United States is under growing strain as Bangkok deepens its military and strategic engagement with China, raising questions about Washington’s future access and influence in mainland Southeast Asia. Once viewed as a cornerstone of U.S. regional air power, the relationship is increasingly shaped by hedging behavior and competing strategic priorities.
The United States and Thailand maintain one of Asia’s oldest treaty alliances, dating back to the Cold War. For decades, the partnership provided Washington with a reliable foothold in Southeast Asia, supporting air, land, and maritime operations across the region. Today, analysts say Thailand’s strategic center of gravity has steadily shifted toward Beijing, testing the durability of an alliance that once appeared unshakeable.
Cold War Roots and Aviation Cooperation
Thailand became a formal U.S. treaty ally during the Cold War and later emerged as a critical hub for American air operations during the Vietnam conflict. Thai bases hosted U.S. aircraft and logistics units, enabling sustained air campaigns and regional mobility at a time when access elsewhere was limited.
In the decades that followed, the partnership expanded beyond wartime necessity. It grew to include advanced air exercises, logistics coordination, and access to key facilities that supported U.S. airlift and refueling missions across the Indo-Pacific. These arrangements helped anchor Thailand within Washington’s broader regional security architecture.
A central symbol of that cooperation remains the Cobra Gold exercises, co-hosted annually by the two countries. Cobra Gold has evolved into the world’s largest multilateral military drills, featuring complex air, maritime, and humanitarian operations involving dozens of participating nations.
Despite their scale, analysts increasingly argue that these exercises no longer reflect the same depth of strategic alignment seen in previous decades, a shift reported by Defence News. Participation continues, but expectations about shared priorities and long-term cooperation have narrowed.
China’s Expanding Defense Footprint
China has emerged as Thailand’s primary defense partner in recent years, particularly after the 2014 military coup prompted Washington to scale back military engagement under U.S. law and policy. The pause created space for Beijing to expand its influence rapidly.
Since then, China has supplied Thailand with a broad range of military equipment, including air defense systems, surveillance radars, armored vehicles, and naval platforms. Aviation cooperation has also grown, with increased Chinese participation in joint exercises and technology transfers.
This growing reliance on Chinese defense systems complicates interoperability with U.S. forces, particularly in air and missile defense. U.S. planners are increasingly concerned about the potential exposure of sensitive aviation, sensor, and command-and-control capabilities when operating alongside Chinese-origin platforms.
Implications for U.S. Air Strategy
The evolving relationship carries direct consequences for U.S. air strategy in Southeast Asia, especially when it comes to access to forward operating locations. U-Tapao, a strategically located naval airfield, has long supported U.S. airlift and aerial refueling missions linking the Middle East and the Pacific.
Analysts now assess that U.S. access to Thai bases during a regional contingency — particularly one involving Taiwan — can no longer be taken for granted. That uncertainty affects operational planning, dispersal strategies, and assumptions about logistics and sustainment in a high-end conflict.
It also shapes decisions about missile basing options and limits the scope of advanced aviation technology the United States is willing to deploy or share with Thai forces.
The F-35 Decision as a Signal
Thailand’s failed bid to acquire F-35 fighter jets in 2023 illustrates these constraints. U.S. officials reportedly weighed Thailand’s close defense ties with China when denying the request, reflecting broader concerns about technology security and intelligence exposure.
The decision sent a clear signal that Washington now views the relationship through a more cautious lens, balancing alliance commitments against the risks of advanced systems operating in mixed technological environments.
A More Symbolic Alliance
Thailand’s strategic tilt toward China is reshaping one of Asia’s oldest defense alliances, with lasting effects on U.S. aviation access, basing flexibility, and regional deterrence planning. While formal ties and joint exercises continue, trust and alignment have weakened on both sides.
As Washington increasingly narrows its regional focus toward maritime flashpoints and island-based allies, mainland Southeast Asia risks sliding down the U.S. strategic priority list. The result is a gradual erosion of American influence, leaving Thailand’s treaty alliance increasingly symbolic rather than operational.
