Eric's Insight: Why is U.S.-led peace on Thai-Cambodian border clash fragile?

Tranquility on the Thai-Cambodian border was shattered by the thunderous roar of heavy artillery on December 8. Shortly afterward, the Royal Thai Air Force deployed F-16 fighter jets in a rare move, launching cross-border airstrikes against military targets in Cambodia.

The new round of border conflict is not only the most severe military conflict between the two countries since 2011, but also a harsh mockery of the U.S.-led diplomatic spectacle held in Kuala Lumpur in October.

When the "American transactional hegemony" collides with Southeast Asia's complex historical entanglements and nationalism, a "quick-fix peace"—built on shaky foundations of mutual distrust and mere interest-swapping—can last less than two months.

Kuala Lumpur witnesses a "peace show" overdrawn

Looking back to October 26, one can see the signing ceremony in Kuala Lumpur was filled with a surreal sense of absurdity.

At that diplomatic show, the major role was neither Thai Prime Minister Anutin Charnvirakul nor Cambodian Prime Minister Hun Manet. Instead, it was U.S. President Donald Trump, who stood prominently at the center.

He not only attended the event as a "witness" but also casually downplayed the mediation of the Thai-Cambodian conflict in his speech, calling it "the 8th war I ended in 10 months." He even went off-script to say, "It’s like… I shouldn’t call it a hobby—it’s more serious than that—but this is something I’m good at and enjoy doing."

For Washington, this peace deal was not crafted for the well-being of the Thai and Cambodian people but to serve Trump’s personal nomination for the "Nobel Peace Prize" and the United States' strategic need to counter China in the geopolitical game in Southeast Asia.

The White House's Fact Sheet released that day unabashedly described the deal as "a landmark achievement that only President Trump could accomplish," directly linking peace with trade agreements and blatantly showcasing the transactional logic that "peace can be bought and sold as a commodity."

However, such "peace" is built on quicksand, and it is doomed to collapse from the very beginning.

Transactional hegemony based on tariff, poor logic

The fragility of the Kuala Lumpur peace agreement stems from its nature as a product of America’s "maximum pressure" and "interest-swapping," rather than a natural outcome of political trust between Thailand and Cambodia.

When the conflict erupted in July, Washington did not engage in traditional diplomacy to bridge differences but instead wielded the "tariff stick" directly.

Trump publicly threatened that if the fighting did not cease, the United States would "end tariff negotiations" and "block trade agreements." This tactic worked in the short term, forcing Thailand and Cambodia—both heavily dependent on the U.S. market—to submit outwardly.

But this approach, described by Cambodian scholars as "transactional hegemony," has a fatal flaw: When it comes to core interests such as territorial sovereignty, national dignity and regime survival, economic calculations can never outweigh political imperatives.

On November 10, the fragile balance was abruptly shattered when Thai soldiers triggered a landmine on the border, resulting in severe injuries and permanent disability.

Faced with soldiers' blood and surging domestic sentiment, Thai Prime Minister Anutin Charnvirakul displayed enough toughness. His statement—"If we can’t sell in the U.S., we’ll sell to other countries"—directly signaled the failure of American tariff threats in the face of a national security crisis.

More ironically, America’s attempt to win over Cambodia through "interest-swapping" inadvertently acted as a catalyst for the rekindling of hostilities.

Who is the arsonist beside the powder keg?

Shortly before the conflict erupted, the United States formally announced on November 7 the lifting of its four-year arms embargo against Cambodia and plans to resume the "Angkor Sentinel" joint military exercise. While the U.S. claimed this was based on Cambodia's "pursuit of peace," it was clear to observers that Washington was attempting to lure Phnom Penh away from China's strategic orbit.

However, at a time of heightened sensitivity along the Cambodian-Thai border, providing military legitimacy and potential arms support to one side of the conflict is undoubtedly a strategic miscalculation that is extremely dangerous.

For Cambodia, this was interpreted as a "confidence-boosting" signal, potentially leading its military to misjudge the situation. Cambodia could have believed it has the U.S. backing and thus took more reckless actions on border issues.

For Thailand, a treaty ally of the United States, this was perceived as an "obvious betrayal."

Bangkok realized that, for geopolitical interests, Washington would not hesitate to arm its potential adversary, and this collapse of trust directly led the Thai military to decide to ignore U.S. "mediation" during this crisis. Thailand even launched F-16 airstrikes without notifying the U.S., seeking a unilateral military solution.

As former Malaysian Transport Minister Ong Tee Keat said: "Relying solely on the United States to use trade agreements as leverage without addressing the root causes of the conflict is, at best, treating the symptoms rather than the disease itself."

Far from stopping the war, the United States, through misguided incentives, handed a match to the Thai-Cambodian powder keg.

Domestic politics makes peace deal more fragile

Beyond the interference of external hegemonic powers, the domestic political dynamics in Thailand and Cambodia also doomed this peace agreement to be short-lived.

In Thailand, Prime Minister Anutin Charnvirakul faces significant pressure from domestic governance.

He must prove himself within just four months to prepare for the upcoming election. Against the backdrop of his predecessor stepping down for being "too soft on Cambodia," Anutin has no choice but to project himself as a "strong man and guardian of the nation". Therefore, when the conflict was reignited, he swiftly declared that "peace is dead" and refused negotiations. This resolute stance is, in essence, a political show staged for domestic voters.

In Cambodia, although Hun Manet has assumed the role of Prime Minister, the influence of his father, Hun Sen, remains ubiquitous.

Faced with domestic economic difficulties and international pressure targeting cross-border scam compounds, Phnom Penh urgently needs an external enemy to divert attention. Hun Sen's "red lines" on social media and his call for the military to "teach the invaders a lesson" serve both to consolidate the Hun family's authority and to rally the public sentiment domestically.

When leaders on both sides are held hostage by nationalist fervor at home, any externally imposed "peace deal" lacks a foundation of public support, and such a deal is destined to be unable to withstand the nationalistic forces.

China's role as a constructive partner

The recurrence of conflict provides a vivid case for observing the different models of influence that are exercised by China and the United States in Southeast Asia.

Compared to the high-profile posturing and "tariff diplomacy" of the United States, China has maintained the stance of a "constructive partner" in addressing the tensions between Thailand and Cambodia.

From Foreign Minister Wang Yi's mediation in Kuala Lumpur in July to the "tea talk" in Anning city, Yunnan province in August, China has consistently emphasized the "ASEAN way," advocating for the rebuilding of mutual trust through dialogue. It has never linked peace with trade sanctions, nor has it pressed hard on one side to win over the other.

Although Western media attempted to smear China's mediating role by posting false news about "Chinese military aircraft transporting ammunition" and by creating a "patron-mediator dilemma," facts speak louder than words.

The "five-point consensus" and demining cooperation promoted by China are low-key but practical initiatives based on the long-term interests of both Cambodia and Thailand.

Amid the new boder conflict, the spokesperson for China's Ministry of Foreign Affairs once again called for restraint and expressed that China would continue to play a role in "its own way." This approach, which neither seeks a political show nor engages in zero-sum games, stands in stark contrast to the short-sighted, opportunistic attitude of the U.S., which seeks "unilateral gains."

A warning in the twilight of hegemony

The rekindling of hostilities between Thailand and Cambodia is not merely a feud between two neighboring countries. It also represents a failed "stress test" of the post-Cold War U.S.-led regional order in Southeast Asia.

Trump attempted to use a businessman's logic to resolve complex disputes over historical sovereignty, believing that high-level deals and a signed agreement alone could secure peace and prosperity.

But facts proved that this "transactional peace" is not only fragile but also harmful. It masks deep-seated contradictions, undermines regional mutual trust, and even exacerbates the intensity of conflict through misguided interventions, such as lifting arms embargoes.

For Southeast Asian nations, this is a harsh lesson: Relying on the "grace" or "coercion" of an external hegemon cannot bring lasting peace and stability. True security can only come from endogenous reconciliation among regional countries based on mutual respect and common interests, as well as a return to an inclusive architecture centered on ASEAN.

When the F-16 jets roared along the Thai-Cambodian border, they not only shattered the "peace agreement" of Kuala Lumpur but also tolled the death knell for American-style transactional diplomacy in Southeast Asia.

For those on the front lines of geopolitical competition, this border clash serves as both a wake-up call and an opportunity to see clearly who is the true builder of lasting peace.

Writing by Qu Fanfu (a political commentator and Ph.D. candidate in Sociology at the University of Cambridge, UK); Editing by Zhang Ruogu, Han Chengyuan, Zu hongbing and Wang Jingzhong; Translating by Wang Shixue