📚The TL;DR📝

1. Thailand: 69,920,998 people. Constitutional monarchy ruled by King Wachiralongkon. Prime Minister Anutin Charnvirakul has governed since September 2025. Borders Laos to the north, Burma to the west, Malaysia to the south, and Cambodia to the southeast.

2. The United States and Thailand have long been close partners, a relationship that dates back to 1818 and became even closer during the Cold War.

3. This relationship frayed after the 1997 economic crisis, as coups and anti-American sentiment became defining features of the Thai political landscape.

4. After a border dispute between Thailand and Cambodia, the United States intervened, threatening tariffs on both countries, which led to a peace deal but alienated the Thai public.

5. Although America’s short-term diplomacy succeeded, it has harmed the U.S.-Thailand relationship, and Thailand is growing closer to China to balance its “bamboo diplomacy.”

📌How Thailand Untied From the U.S.📌

Artillery shells shattered the ancient peace of the Hindu Ta Muen Thom temple, located on the Cambodia-Thailand border, in July 2025. Once a site of interreligious and international peace and reflection, the temple instead became a battlefield for the first potential land war in Asia in decades.

As America’s oldest Asian ally, Thailand expected U.S. support against Cambodia, a close Chinese ally in the region. But President Trump instead threatened crippling tariffs on both countries unless they came to the negotiating table. His ultimatum succeeded, and the two countries agreed to a ceasefire during the Association of Southeast Asian Nations (ASEAN) Summit in late October. 

While the Trump administration boasted of another successful peace deal, America’s harsh demands on Thailand have fostered bitter resentment that could upend the ancient alliance. If America loses its footing in Bangkok, others could follow—and Beijing’s growing control over Thai supply chains and agriculture would be felt not only in Asia, but in American homes and wallets.

Elephants and Dominos

America’s friendship with Thailand dates back to 1818, when an American merchant ship arrived in Bangkok to purchase sugar. The encounter led to the two countries signing the Treaty of Amity and Commerce in 1833, the United States’ first-ever pact with an Asian country. 

During much of the 19th century, the ties between the two countries were defined by non-colonial friendship. When King Rama IV ascended to the throne in 1851, the country faced intense Western imperial pressure, as France had conquered Vietnam and the British had seized Burma.. He modernized Thailand and sought diplomatic ties with Western countries to avoid a similar fate.

Siam began to view the United States as a friendly counterweight to the hostile European powers. King Mongkut even offered war elephants to President Lincoln in 1862, during the American Civil War— a gift Lincoln politely declined. American scholars and diplomats advised the Siamese court on drafting legislation and updating its constitution to align with Western standards. The friendly relationship led Siam to side with the Allied powers during World War 1, further enhancing cooperation and aligning their interests. 

Although Thailand aligned with Japan during World War 2, the United States and Thailand quickly resumed their partnership as communist regimes took power in China and North Vietnam. Thailand supported the American war effort in Korea and would become integral to America’s strategy in Southeast Asia. American strategists feared a “domino effect" in Southeast Asia, where a communist takeover in one country would lead to its neighbors falling to communism.

The escalation of the war in Vietnam seemed to confirm these fears in both Washington and Bangkok. As North Vietnam and its allies threatened Cambodia and Laos, Thailand became a centerpiece of American strategy. The country hosted 50,000 American troops during the conflict, and American bombers launched missions from Thai airbases. The United States offered billions in military and development aid in Thailand, hoping to keep the country prosperous and stable. 

U.S.-Thai cooperation continued despite American failure in Vietnam. In 1982, the United States and Thailand launched Cobra Gold, an annual joint exercise between the two countries and other American allies in Southeast Asia. Signs of strain in the relationship were beginning to appear, however. In 1997, Thailand suffered an economic collapse driven by dollar-denominated debt, and the Thai public began to resent the close economic ties that had led to the crisis and the IMF-imposed austerity program. The financial crisis led to protracted political instability, and the military began interfering in domestic politics. 

Bangkok Blues

The effects of this persistent instability further frayed U.S.-Thai ties. In the aftermath of the 2014 Thai election, Gen. Prayut Chan-o-cha led a military coup against Prime Minister Yingluck Shinawatra’s elected government. The U.S. immediately suspended $3.5 million in military assistance, halted joint programs, and urged a rapid return to democracy. Thailand’s military government defied these demands, asserting that the country could handle its internal affairs and politics and rebuffing American interference.

Alienated from its oldest ally, the junta turned towards new potential partners. The Chinese government turned a blind eye to the coup and saw the opportunity to develop economic and political links with Thailand. In 2015, one year after the junta’s takeover, Thailand and China conducted a joint air exercise, and the two militaries now closely collaborate. Thailand welcomed Chinese investment as part of the Belt and Road Initiative, and allowed the Confucius Institutes to offer Mandarin instruction at Thai universities.

Donald Trump’s election in 2016 and Thailand’s guided transition to democracy in 2019, meant relations recovered somewhat. Washington adopted a pragmatic tone toward the Thai junta, restoring military cooperation. Although the United States did not prioritize Southeast Asia during the Biden administration, relations were generally positive and productive. Bangkok continued to balance between the two powers, signing expansive agreements on green energy, semiconductors, and high-speed rail, which have led to over $10 billion invested in the country through the Belt and Road framework.

Peace at Any Price?

For a brief moment, it seemed that Thailand could successfully balance between the United States and China. This ended with the outbreak of violence between Thailand and Cambodia in July 2025. A mine explosion injured 5 Thai soldiers, and Thailand quickly retaliated with artillery strikes against Cambodian positions.  As war loomed, the United States opted to force a settlement, applying heavy diplomatic pressure. Trump personally inserted himself in the negotiations, threatening punitive 36% tariffs on imports from both countries. This threat compelled Thailand and Cambodia to accept U.S.-mediated talks in Kuala Lumpur, Malaysia. 

Although these efforts led to a settlement, they infuriated the Thai government. Thai Prime Minister Anutin Charnvirakul insisted that Thailand would not participate in further peace talks unless Cambodia complied with earlier agreements and withdrew troops from Thai territory. He also lambasted Trump’s remote intervention, quipping that the U.S. “is in another continent far away from Thailand.” While the ultimatum indeed forced a truce, the U.S.’s approach has nonetheless left a sour taste in Thai opinion.

China played a more subtle, calculated role. To avoid public confrontation, Beijing quietly extended diplomatic and humanitarian assistance to both Thailand and Cambodia, using its influence with both countries under the guise of neutrality. China is Cambodia’s largest investor, and the ruling Hun family is closely tied to Chinese business interests. Cambodia also hosts a joint military base in Ream, which opened in April. This leverage helped force Cambodia to the negotiating table.

🌎Why It Matters🌎

Since the conflict, Thailand has tightened trade and diplomatic links with China. Prime Minister Charnvirakul met with Chinese Ambassador Zhang Jianwei in mid-October 2025, pledging to “enhance all-round cooperation” while welcoming China’s role in post-conflict stabilization within the ASEAN framework. 

This realignment threatens U.S. efforts to maintain its partnerships in the Indo-Pacific. The alliance between Thailand and the United States was once the linchpin of U.S. strategy in the region, with troops and aircraft stationed there. U.S. influence in Thailand also helped promote democratization, both in the wake of World War II and in the early 2000s.

Thailand’s economic collapse in the 1990s marked the beginning of the end for the U.S.-Thailand alliance. While the United States has anchored its commitment to democratic values, China has leveraged Thailand’s political instability as an avenue for expanding its influence in the country. China’s existing alliance with Cambodia, alongside this new diplomatic push, suggests that China is working to position itself as the primary geopolitical partner for ASEAN countries. If the United States continues to pursue the same aggressive strategies, it may achieve success on immediate priorities, like the ceasefire deal reached in Kuala Lumpur. However, its ability to promote both long-term alliances and democracy in the region will likely fade.

The effects of the new Thai-Chinese partnership are already being felt. In February, Thailand deported 40 Uyghur asylum seekers back to China, suggesting that as the relationship between the two countries deepens, Thailand could become a partner in China’s domestic repression efforts. Without a concerted U.S. effort to rebuild and renegotiate the alliance, Thailand’s “bamboo diplomacy” will continue to bend towards Beijing.