Indonesia is facing a wave of territorial disputes between its regions, sparked by a recent border resolution between Aceh and North Sumatra. The conflict, which saw four contested islands briefly transferred to North Sumatra before being returned to Aceh, has exposed deep flaws in the country’s legal framework for defining regional boundaries. As other provinces and regencies press their own claims, experts and officials are calling for urgent regulatory overhaul to prevent escalating tensions in a nation with strong local identities.
Aceh Dispute Sets a Precedent
The border disagreement between Aceh and North Sumatra came to a head last week when the Home Ministry issued a decree transferring ownership of four islands to North Sumatra. The decision triggered immediate backlash from Aceh residents and officials, who viewed it as a violation of historical and administrative boundaries. Protests erupted, raising fears of broader unrest in a region with a history of separatist tensions.
In response, President Prabowo Subianto intervened directly, conducting a video conference with the governors of both provinces while en route to Russia. The meeting resulted in an agreement to return the islands to Aceh, a decision hailed as a temporary de-escalation but criticized for lacking a long-term legal basis. “Prabowo gives nod to Aceh regaining control of disputed islands” reported The Jakarta Post, underscoring the President’s hands-on approach to a sensitive issue. 
However, the resolution has had a ripple effect, emboldening other regions to challenge the same 2025 ministerial decree. Critics argue that the decree fails to account for regional spatial plans or historical boundaries, setting the stage for a series of disputes that could undermine Indonesia’s regional autonomy framework.
East Java and Bangka Belitung Step Forward
One prominent case involves two regencies in East Java, Trenggalek and Tulungagung, which are locked in a dispute over 13 uninhabited islands off the province’s southern coast. Previously under Trenggalek’s administration, the islands were reassigned to Tulungagung by the recent decree, reigniting a conflict dating back to 2022. Despite mediation by the East Java administration, negotiations remain stalled.
“We’ve sent a letter to the Home Minister. We’re not speculating on legal action yet while waiting for a response from the central government” said Trenggalek regency secretary Edy Soepriyanto, as quoted by Kompas.com. The statement reflects a cautious approach, though local frustration is palpable.
Similarly, the Bangka Belitung Islands provincial administration has renewed its claim over the Tujuh Islands, a cluster of 15 mostly uninhabited islands currently under Riau Islands’ jurisdiction. The 2025 decree reaffirmed a 2022 decision, but Bangka Belitung argues that the islands are geographically closer to their province and that residents of the only inhabited island, Pulau Pekajang Kecil, depend on them for trade and supplies. Governor Hidayat Arsani has pledged to pursue the matter through legal channels, stating, “We will not involve the President. We will pursue this through legal means, and we will abide by the ruling” as reported by Kompas.com.
Systemic Issues in Boundary Laws
At the heart of these disputes lies a fundamental problem: Indonesia’s legal framework for defining regional boundaries is outdated and imprecise. Herman Surparman of the Jakarta-based think tank Regional Autonomy Watch (KPPOD) pointed out that many laws use vague geographic references without specifying exact coordinates. “Border disputes arose in part because these laws define boundaries in overly general terms, such as ‘north of this’, ‘south of that’, without clear coordinates or details. We need better laws” he told The Jakarta Post.
This lack of clarity has led to overlapping claims and administrative confusion, particularly in a country as geographically and culturally diverse as Indonesia. With over 17,000 islands and hundreds of distinct ethnic groups, regional identities often run deep, making territorial disputes not just administrative but also deeply emotional issues.
Political analyst Agung Baskoro of Trias Politika Strategis emphasized the need for a bottom-up approach in addressing these conflicts. “The Aceh-Sumut case showed what happens when decisions are made without involving the people on the ground. The central government can’t just draw administrative lines on a map and expect people to quietly accept it, especially in regions with strong local identities” he explained. His comments highlight a broader tension between Jakarta’s central authority and the push for greater regional autonomy, a key issue since Indonesia’s decentralization reforms in the early 2000s.
Government Response and Legislative Proposals
The Home Ministry has acknowledged the growing number of disputes and promised a measured response. First Deputy Home Minister Bima Arya Sugiarto stated that the ministry is studying the cases and will adopt a “cautious” approach, drawing lessons from the Aceh resolution. However, specifics on how the ministry plans to address systemic issues remain unclear, leaving regional administrations in limbo.
Meanwhile, the House of Representatives’ Commission II, which oversees home affairs, has proposed two potential solutions. Chairman Rifqinizamy Karsayuda outlined the options as either creating a new law to standardize regional boundaries or revising all 545 existing laws that govern regional delineations. Both approaches are ambitious, but they face significant hurdles given the complexity and political sensitivity of redefining boundaries across the archipelago.
A new standardized law could provide clarity by mandating the use of precise geographic coordinates and involving local stakeholders in the process. However, revising hundreds of existing laws would be a monumental task, requiring extensive consultation and potentially inflaming further disputes in the interim. The path forward remains uncertain, and the government will need to balance legal reform with the immediate need to manage tensions on the ground.
Broader Implications for Regional Autonomy
These border disputes come at a time when Indonesia is grappling with broader questions about the balance of power between Jakarta and its regions. Decentralization, a cornerstone of post-1998 reforms following the fall of Suharto, aimed to empower local governments by granting them greater control over resources and administration. However, inconsistent policies and top-down decisions, such as the 2025 ministerial decree, have fueled perceptions that Jakarta is clawing back influence, as noted in recent analyses by The Jakarta Post.
If left unresolved, these disputes could erode trust in the central government and exacerbate regional inequalities. In areas like Aceh, which negotiated special autonomy as part of a 2005 peace agreement ending decades of conflict, territorial issues carry added weight, risking the fragile stability achieved in recent years. Similarly, in East Java and Bangka Belitung, unresolved claims could deepen local grievances, potentially spilling over into broader political or social unrest.
Moreover, the economic stakes are significant. Control over islands and border areas often translates to access to natural resources, fishing rights, and tourism revenue. For instance, the Tujuh Islands may be largely uninhabited, but their proximity to trade routes and potential for development makes them a valuable asset for Bangka Belitung. Losing such territories can have long-term economic consequences for local communities, adding another layer of complexity to these disputes.
Looking Ahead: A Test for Indonesia’s Governance
As Indonesia navigates this wave of border disputes, the central government faces a critical test of its ability to balance regional aspirations with national unity. The Aceh-North Sumatra resolution may have averted immediate conflict, but it has also opened a Pandora’s box of claims that could take years to settle. Without a clear and inclusive legal framework, the risk of further tensions looms large.
Experts agree that involving local communities and adopting transparent, data-driven approaches to boundary delineation are essential steps forward. Yet, with political and cultural sensitivities at play, any solution will require careful diplomacy and a commitment to fairness. As the Home Ministry and House of Representatives deliberate on legislative reforms, the voices of those on the ground—farmers, fishers, and local leaders—must not be overlooked.
For now, the nation watches as these disputes unfold, raising fundamental questions about how Indonesia defines itself in an era of decentralization. Will Jakarta rise to the challenge of creating a cohesive framework for its diverse regions, or will territorial divisions continue to test the fabric of its governance?
