The provincial boundary dispute between Aceh and North Sumatra has resurfaced. Four small islands, Mangkir Gadang Island, Mangkir Ketek Island, Lipan Island, and Panjang Island, were officially registered as part of North Sumatra Province under the Ministry of Home Affairs Decree No. 300.2.2-2138 issued in April 2025. The decree immediately triggered protests from the Aceh Government and revived an unresolved territorial boundary dispute.
A geodesy expert from Universitas Gadjah Mada (UGM), Dr. I Made Andi Arsana, outlined the history of the conflict and the factors suspected to underlie the dispute over the four islands, and according to him, the Aceh–North Sumatra dispute originated during Indonesia’s national geographic data collection process conducted by the National Team under President Susilo Bambang Yudhoyono in 2008.
At that time, the National Team was tasked by the government with compiling an administrative report on the number of islands in Indonesia for submission to the United Nations (UN).
The procedure required provincial governments to report the number of islands within their respective administrative areas. This process was carried out sequentially across provinces throughout 2008–2009.
“At that time, the National Team’s role was solely to record data, not to determine ownership of islands. Therefore, if an island had already been registered and later submitted by another province, it would not be re-recorded because it had already been counted,” Dr. Arsana explained on Tuesday (Jun. 17).
North Sumatra registered a total of 213 islands, including the four disputed islands, as part of the province on 14–16 May 2008. During the same period, the Aceh Government, on 20–22 November 2008, did not register the four islands as part of its administrative territory.
Instead, four islands named Rangit Besar, Rangit Kecil, Malelo, and Panjang were registered. However, according to Andi, there is another version of events suggesting that Aceh had intended to register the disputed islands.
The initial data collection results were verified by North Sumatra in 2009. Meanwhile, the Aceh Government submitted a request to change the names associated with the coordinates of the four previously registered islands.
The coordinates of Rangit Besar, Rangit Kecil, Malelo, and Panjang were renamed Mangkir Besar, Mangkir Kecil, Lipan, and Panjang. However, the name changes were not accompanied by changes in the coordinate points, which confused the Geospatial Information Agency (BIG).
Dr. Arsana suspects that Aceh may have intended to include the four disputed islands within its territory.
“This is where the root of the problem lies. North Sumatra registered the island first, then Aceh submitted data using incorrect coordinates. Administratively, the data that is consistent is considered more credible,” Dr. Arsana explained.
As all data since 2008 continued to refer to North Sumatra, the Ministry of Home Affairs reflected this information in its official decrees. Due to the ongoing dispute, BIG stated in its 2021 report that the four disputed islands are part of Indonesia, without assigning them to either Aceh or North Sumatra.
Subsequently, Aceh submitted a document dated 1992 in 2022. The document contains a provincial boundary agreement between Aceh and North Sumatra. Notably, the map included in the deal depicts Aceh’s territory as encompassing the four disputed islands. This document is the basis of Aceh’s claim over the islands.
However, the document submitted is only a black-and-white copy, not the original. Dr. Arsana added that if the document is valid, the North Sumatra Government and the Ministry of Home Affairs, which were also signatories, should possess the original version.
“If Aceh succeeds in locating the original document, Aceh’s claim could then be considered,” he said.
Beyond administrative issues, Dr. Arsana explained that the Aceh Government has carried out activities on the four islands.
“The islands are uninhabited, but Aceh has conducted activities there since well before 2008. However, it must be emphasized that effective control, such as activities or management of an area, can only be applied if legal ownership has been clearly established,” he stated.
According to Dr. Arsana, the current polemic still places administrative authority with North Sumatra. Therefore, resolving the conflict requires the original version of the document submitted by Aceh, or other documents concerning the four islands issued before 2008.
Author: Tasya
Editor: Gusti Grehenson
Photographer: Firsto Adi