June 24, 2025
JAKARTA – The recently resolved border dispute between Aceh and North Sumatra has reignited long-simmering territorial tensions in other parts of the country, highlighting an urgent need for a clear legal framework governing regional boundaries.
Tensions rose last week after the Home Ministry issued a decree that transferred the ownership of four contested islands from Aceh to North Sumatra, prompting protests from Aceh residents and officials.
In a bid to prevent the dispute from escalating, President Prabowo Subianto, while en route to Russia, led a meeting between Aceh and North Sumatra governors through video conference that resulted in an agreement to return the islands to Aceh.
Days after the dispute was settled, other regions stepped forward with unresolved claims of their own and challenged the same ministerial decree, which they say fails to reflect spatial plans of the regions and historical administrative boundaries.
Waves of disputes
One of the most notable cases involves an old dispute between two neighboring regencies in East Java over 13 uninhabited islands located off the southern coast of the province.
The contested islands, previously considered part of Trenggalek, were placed under Tulungagung’s administration by the 2025 ministerial decree, prompting renewed protests from the Trenggalek administration over the dispute that goes back to as early as 2022.
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Despite multiple rounds of talks, including mediation by the East Java administration, negotiations remain deadlocked. Trenggalek has since sent a formal letter to the Home Ministry requesting to review the decree.
“We’ve sent a letter to the Home Minister. We’re not speculating on [legal action] yet [as we are still] waiting for a response from the central government,” Trenggalek regency secretary Edy Soepriyanto said last week, as quoted by Kompas.com.
The border dispute in Aceh has also prompted the Bangka Belitung Islands provincial administration to renew its push to reclaim the Tujuh Islands, a cluster of 15 small islands, mostly uninhabited, that are placed under the jurisdiction of Riau Islands province by the 2025 ministerial decree. This decision reaffirmed a previous ministerial decision in 2022.
Bangka Belitung is now preparing to challenge the designation of the island cluster at court on the grounds that Tujuh Island lies closer to Bangka Belitung and that residents of the only inhabited island, Pulau Pekajang Kecil, rely on the province for supplies and trade.
“We will not involve the President. We will pursue this through legal means, and we will abide by the ruling,” Bangka Belitung Governor Hidayat Arsani said as quoted by Kompas.com.
Regulatory overhaul
Herman Surparman of Jakarta-based think tank Regional Autonomy Watch (KPPOD) highlighted the need for a clearer legislation governing regional boundaries, noting that many prevailing laws that define regions still draw the boundaries using vague geographic references without specifying 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 on Saturday.
Read also: Prabowo gives nod to Aceh regaining control of disputed islands
Political analyst Agung Baskoro of think tank Trias Politika Strategis emphasized the importance of the central government adopting a bottom-up approach when defining regional boundaries.
“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,” Agung said.
First Deputy Home Minister Bima Arya Sugiarto said on Saturday the ministry is carefully studying the resurfaced border disputes, adding that it would take a “cautious” approach and draw lessons from the Aceh case.
Rifqinizamy Karsayuda, chairman of House of Representatives’ Commission II overseeing home affairs, said the commission has proposed two legislative options: Making a new law standardizing regional boundaries or redefining each of the boundaries by revising all 545 existing laws governing the regions.