In late May, Southeast Asian foreign ministers met in Kuala Lumpur to unveil the ASEAN Community Vision 2045 plan. This plan, known as ACV 2045, is intended to serve as a roadmap for ASEAN nations to enhance their economic productivity and ensure regional stability.
However, against the backdrop of this meeting, Thailand and Cambodia were embroiled in a deadly border clash that reignited long-simmering tensions. This ongoing standoff is not an isolated occurrence. Several ASEAN nations share similar territorial grievances with their neighbors, resulting in a range of consequences, from diplomatic protests to armed conflicts.
Amid an increasingly complex external geopolitical environment and internal ambitions for greater integration, recurring territorial disputes pose a significant challenge that undermines ASEAN centrality and hinders its ability to address key issues and implement initiatives effectively.
It is insufficient to rely solely on bilateral mechanisms or external institutions to resolve these incidents. ASEAN must strengthen its existing mechanism, the High Council, to ensure peaceful resolution and equip itself to address external challenges effectively.
This was exemplified on May 28, 2025, when a fatal exchange of gunfire took place between Thai and Cambodian border guards. The dispute concerns the Angkor-era Preah Vihear temple complex and dates back to colonial-era mapping efforts.
Despite the International Court of Justice’s (ICJ) 1962 ruling that Preah Vihear belongs to Cambodia, demarcations of the northern border were not established, and conflict over the area previously flared up in 2008 and 2011.
In response to the latest incident, Thailand instituted border restrictions, electricity flows have been halted in areas, Cambodian imports of fruits and vegetables have been blocked and Cambodia has banned Thai movies and TV shows.
Attempts to resolve the dispute bilaterally, such as through the Joint Border Commission, have so far failed. Cambodia’s decision to bring the dispute before the ICJ for adjudication was rebuked by Thailand, which insists the issue should be resolved bilaterally.
This incident is one of many that threaten to resurface and stir instability among ASEAN nations. Notably, the South China Sea also remains a contested area for several Southeast Asian countries. Although China’s gray zone activities have made it the center of attention, territorial disputes between ASEAN nations persist.
One area of particular contention is the Spratly Islands, which are claimed to varying degrees by Vietnam, China, Malaysia, Brunei and the Philippines. In November 2024, Malaysia lodged a complaint with Vietnam over its expansion of artificial islands. Further, despite agreeing to cooperate on South China Sea issues, Hanoi sent a letter to Manila in May 2025 disputing its actions at Sandy Cay.
These incidents come in stark contrast to the lofty goals set forth by ACV 2045, which was adopted during the 46th ASEAN Summit and succeeded the 2015 ASEAN 2025: Forging Ahead Together plan.
The ACV 2045 is a blueprint for the prosperity of ASEAN, encompassing four pillars: political security, economics, socio-culture, and connectivity and institutional capacity building. The document builds on past priorities while putting forth a new emphasis on regional leadership in global affairs and a focus on digital and green economies.
Taken together, these initiatives would help achieve ASEAN’s stated goal of becoming the fourth-largest economy in the world and enhance its ability to influence regional dynamics. Despite these ambitions, further integration of Southeast Asia to achieve these goals will be impossible if territorial issues continue to plague ASEAN centrality.
Notably, this desire to increase the bloc’s ability to resolve territorial disputes is already a key priority to some in ASEAN. For example, during the May 2025 ASEAN Maritime Security Dialogue, Malaysia’s Deputy Director-General of National Security Hamzah bin Ishak suggested a five-year timeline for resolving disputes.
Although the idea was deemed overly ambitious by other attendees, their willingness to engage in the discussion shows that regional actors understand the essential nature of resolving these disputes.
However, ASEAN already has a mechanism to do so through the ASEAN High Council. Yet, in practice, the High Council has never been used to resolve any disputes. Instead, countries have either attempted to utilize established bilateral mechanisms or external institutions, namely the ICJ, to resolve these issues.
The recent flare-up between Cambodia and Thailand illustrates that these efforts are insufficient. Not only does this problem erode ASEAN centrality as outside players intervene to resolve issues in Southeast Asia, but the lack of universal recognition among regional states, combined with the absence of a binding mechanism, means many of these issues remain unresolved.
ASEAN should work to better operationalize the High Council. First, the council must resolve the lengthy timeline required to bring the case to a conclusion. These regional disputes often deteriorate rapidly and the risk of escalation is high.
As such, the requirement for a party to give at least 14 days of written notice before invoking the dispute settlement process is too long. Furthermore, the chairperson is only required to convene a meeting within six weeks of receiving written confirmations.
This timeline is excessive and countries will not sit idly by while the council takes weeks to convene. A more streamlined timeline must be implemented to ensure that states with grievances can meet and resolve disputes before escalation occurs.
The High Council should also seek to strengthen its mandate and the expertise of its members. The ad hoc selection of representatives for the council is inadequate both in meeting the urgency required to resolve disputes promptly and in providing the necessary expertise for practical solutions.
ASEAN has already acknowledged in one instance that to address an issue seriously, permanent officials or envoys are needed; hence, the establishment of a permanent Myanmar envoy. The resolution of territorial disputes should be approached with the same mindset.
The creation of a permanent mediation panel composed of legal experts, regional historians and international scholars would better equip it to handle disputes in a timely and efficient manner. Moreover, the chairperson could be rotated every three years, just like the Myanmar envoy.
With the advent of AVC 2045 and the resurgence of Cambodia-Thailand border tensions, the time is now to reinvigorate the High Council, enabling ASEAN to regain its ability to resolve its own regional disputes.
Failure to act now will prevent ASEAN from effectively addressing its most pressing issues, such as US-China geopolitical competition and maximizing the economic capabilities of its member countries. The bloc holds the procedural solution within its grasp; it now must build confidence in the High Council by committing to refining and empowering it.
Nathaniel Schochet is an associate analyst at CJPA Global Advisors. He previously worked as a program administrator for the Indo-Pacific Security Program at the Center for a New American Security (CNAS) and is a part of the Pacific Forum’s Young Leaders Program.
