Regional Problems, Regional Solutions: ASEAN’s Quiet Victory in Southeast Asia

In a world where regional conflicts have become politicized due to foreign influence as well as arena for great power strategic rivalry, it is refreshing to see the latest Thailand-Cambodia border war be resolved at the hands of ASEAN’s regional leadership. Had the ceasefire not been brokered by ASEAN leadership, it risked marginalization by external powers seeking to exploit the resulting vacuum. This illustrates the organization’s continued relevance serving as a vital force for peace particularly in resolving interstate disputes.

The five-day war between Thailand and Cambodia in late July showcases the fragility of frozen conflicts marked by unresolved colonial-era border disputes. More than 300,000 people were displaced and 38 civilians killed before ASEAN chair Malaysia, backed by the United States, China, and other regional leaders, secured an unconditional ceasefire.

Unlike the brief skirmishes of 2011, this confrontation saw unprecedented escalation. Cambodia’s reliance on outdated Soviet-era weaponry resulted in imprecise strikes that devastated civilian areas, while Thailand responded with precise strikes against Cambodian military sites. Both sides, however, intensified the confrontation by deploying high-intensity weaponry—such as Thai F-16s and Cambodian BMP-3 vehicles—and laying landmines, signaling an unprecedented escalation.

The conflict also revealed the extent to which domestic politics shaped escalation. Cambodia’s leadership transition to Hun Manet left power still concentrated in Hun Sen’s hands, with the regime facing economic decline and resurgent opposition. The assassination of opposition figure Lim Kimya in Thailand purportedly by a hitman with ties to the Cambodian government, earlier this year illustrates the regime’s fragility, shaping Phnom Penh’s increasingly aggressive posture.

For Cambodia, Paetongtarn’s leadership offered an opportunity. Perceived as weak, her leaked call disparaging Thai generals while flattering Hun Sen gave Phnom Penh an opening for a short border clash. The skirmish enabled Hun Sen to rally nationalist sentiment, portray Thailand as an aggressor, and divert attention from domestic problems. Such appeals to nationalism and sovereignty have long served to consolidate regime legitimacy.

Adding to Cambodia’s calculus were its struggling economy, rising political opposition, and its historical location – wedged between stronger neighbors, Thailand and Vietnam. Due to its violent past, which included a devastating war with Vietnam and decades of rule by the Khmer Rouge, the country has a political culture where power is seen as a sign of survival. Any perceived vulnerability, especially regarding border conflicts or sovereignty, may be seen as an existential danger to both the state and ruling elite. For the Hun Sen dynasty, showing might at the frontier was more of a political necessity than a choice.

Though on the other hand, Thailand too has its own strategic reasons for prolonging the dispute. While Cambodia once again appealed to the International Court of Justice (ICJ) for this year’s border dispute, Thailand rejected arbitration, insisting on bilateral negotiations to protect its sovereignty. Past ICJ rulings in 1962 and 2013, which awarded Cambodia limited victories around Preah Vihear, reinforced Bangkok’s reluctance to accept external adjudication. Bilateral talks, however, tend to drag on, especially when political will is lacking.

Additionally, Thailand’s foreign policy has long been constrained by chronic political instability and factionalism. The civilian government led by the Shinawatra family has faced persistent opposition from entrenched military and royalist elites, resulting in policy paralysis.

With 13 coups and 20 constitutions since the 1930s, Thai politics is characterized by volatility, stagnancy and institutional fragmentation, fostering a risk-averse approach to national security. Foreign policy decisions, particularly those involving sovereignty or bilateral commitments, are often stymied by elite contestation. The military, despite periods of civilian rule, remains a dominant actor with institutional autonomy and strategic interests that makes any foreign policy decision making as well as bilateral agreements involving national sovereignty more complicated. Consequently, leaders tend to prioritize domestic factional appeasement over risky foreign policy initiatives.

On a more positive note, the swift unconditional ceasefire brokered by Malaysia reaffirmed ASEAN centrality and relevance. Regional conflicts, when managed by regional actors, foster greater legitimacy and trust. While ASEAN’s non-interference principle has often constrained responses to domestic crises like Myanmar, interstate conflicts present a different dynamic. Because they do not intrude directly into domestic governance, they provide space for constructive dialogue and resolution.

Malaysia’s role under Prime Minister Anwar Ibrahim was instrumental, with his longstanding relationships with Thai and Cambodian leaders providing the necessary credibility and trust to facilitate mediation between the two parties.Historically, Malaysia has a track record of mediating separatist conflicts in southern Thailand and the Philippines. By contrast, U.S. or Chinese-led involvement—however well-intentioned—would have likely prolonged tensions by politicizing the process (cue Trump’s desire for a nobel peace prize). Unlike Indonesia’s 2011 mediation of the Thai–Cambodia border dispute, this year’s resolution advanced further by including ASEAN observers stationed along the border, which both sides agreed to unlike in 2011. The agreement to accept these observers marks a significant evolution in ASEAN practice, resembling African Union–led peacekeeping missions in which regional institutions assume ownership of local security crises.

Trump’s tariff threats against Cambodia and Thailand added pressure to end hostilities, with initial warnings of 36% tariffs later reduced to 19% after the ceasefire. Yet these threats were not decisive. The ceasefire emerged primarily from an ASEAN-led process that produced both a cessation of fighting and a “day-after” monitoring frameworkthrough ASEAN defence attachés. Unlike the recent Azerbaijan–Armenia ceasefire, where the U.S. stepped in to fill a Russian vacuum, Southeast Asia demonstrated no such void. ASEAN centrality remained intact and its diplomatic strength prevailed, with both disputing parties preferring regional mechanisms over external arbitration. Neither the U.S. nor China could credibly assume this role, given their deep economic entanglements with both states. Instead, the great powers remained supportive but peripheral, while ASEAN delivered a conflict resolution process rooted in regional ownership rather than external dominance. The silver lining is, when ASEAN leads, superpowers step back and watch.

The management of the Thai–Cambodia conflict by ASEAN highlights the significance of regional frameworks as a force for peace in Southeast Asia, allowing for comparison with other intergovernmental organisations, such as the European Union (EU). ASEAN functions with a much lighter institutional framework, adhering to principles of non-interference and consensus. Unlike the EU, a supranational court is absent, yet ASEAN’s role in conflict resolution for the Thai-Cambodia ceasefire shows that region-led diplomacy can de-escalate conflicts and deliver credible outcomes. The conflict highlights how ASEAN functions as a platform where domestic politics, nationalism, and historical grievances can be managed within a regional structure.

The distinct differences between the EU and ASEAN are that the EU is strong because of its detailed legal and institutional systems whereby countries must follow EU laws, and penalties can be enforced while ASEAN depends on trust, agreement, and quiet diplomacy. This limits its ability to handle internal issues like the crisis in Myanmar, but it works well in interstate conflicts where domestic issues is respected. However, both show that regional solutions built on trust and legitimacy are the most effective tools for conflict prevention. The successful ceasefire not only reinforces ASEAN’s central role in regional stability but also reflects a broader global trend where regional organizations act as key pillars of peace. Such outcomes lend weight to the characterization of ASEAN as a ‘catalyst for peace’.

DISCLAIMER: All views expressed are those of the writer and do not necessarily represent that of IIPA and this platform.

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Authors

Hazwan Dani Abdul Kadir is a PhD candidate at the University of Canterbury, New Zealand. His current research focuses on conflict escalation, de-escalation, small state security, and state behaviour and response in asymmetric and conventional conflict environments.

Edna Luah is a PhD candidate at the University of Canterbury, whose research explores how international organizations adapt, with a focus on case studies from Europe and Southeast Asia.

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