“Indonesia Ratifies Maritime Border Treaty with Singapore”, a Commentary by Mustafa Izzuddin

Commentary 2017/1, 5 January 2017 

On 15 December 2016, the Indonesian parliament (DPR) ratified a sea border treaty between Indonesia and Singapore to demarcate the maritime boundary in the eastern section of the Singapore Strait, covering a 9.45 km stretch between Changi and Batam. This ratification, achieved 27 months after this treaty was signed in September 2014, took place during a recently-concluded month-long parliamentary session in which DPR legislators passed only two bills into law, one of them being this bilateral maritime treaty, while delaying forty others. What then were the reasons for prioritising the ratification of this treaty bill?


As the largest Southeast Asian country, Indonesia viewed the ratification as of much importance as it helped demarcate maritime boundaries for the purposes of safeguarding its sovereignty and preserving its territorial integrity. Indonesia has now finally resolved all its bilateral maritime boundaries with Singapore, apart from the one between Indonesia’s island of Bintan and Singapore’s Pedra Branca. The latter requires Singapore to first negotiate with Malaysia on delimiting maritime boundaries, after Pedra Branca was ruled in favour of Singapore by the International Court of Justice (ICJ) in May 2008.

This is the third maritime boundary agreement between Indonesia and Singapore. In May 1973, under the governments of President Suharto and Prime Minister Lee Kuan Yew, Indonesia and Singapore agreed on delineating the maritime boundary along the central part of the Singapore Strait. After Indonesia ratified the agreement in December 1973, Singapore followed suit the ensuing year in August 1974. In March 2009, a second agreement was reached on the maritime boundary in the western section of the Singapore Strait, covering the water stretch between Singapore’s Sultan Shoal and Indonesia’s Pulau Nipa. This maritime agreement was subsequently ratified by both countries in August 2010.

The good rapport between the political leaders, Prime Minister Lee Hsien Loong and President Susilo Bambang Yudhoyono and then Lee and Jokowi Widodo, facilitated, if not hastened, the ratification of this latest maritime treaty. This treaty ratification was realised about a month after Lee and Jokowi held their first Leaders’ Retreat in November 2016. The ratification of the treaty can also be attributed to domestic political support within Indonesia. Deep-seated nationalist sentiments simmering in Indonesian society requires the government to ensure that Indonesia does have clearly-defined borders so as to safeguard its sovereignty and preserve its territorial integrity. Indonesia is then better able to protect its natural resources and avoid a situation in which it loses territory. Losing Timor-Leste through independence from Indonesia, and also Sipadan and Ligitan to Malaysia after a ruling by the ICJ remain steeped in the historical memory of many Indonesians. Without doubt, the ratification of this maritime treaty would have sat well with the general Indonesian public.

This ratification may also be related to Indonesia’s concerns about the security of the Natuna islands and surrounding waters. Chinese vessels barging into Indonesian waters and under-taking illegal fishing disconcerted the Indonesian authorities. Against this backdrop, which threatens to undermine Indonesia’s sovereignty, it made sense to resolve swiftly any pending maritime boundaries.

The practice of maritime border diplomacy is a cornerstone of Indonesia’s foreign policy. As the idiomatic expression goes, good fences make good neighbours. The three agreements – resolving three key stretches of the Singapore Strait – are tantamount to securing maritime fences between two maritime countries. With the maritime boundaries now clearly demarcated, both countries can shift their focus fully on strengthening other areas of cooperation, not least in the economic sphere.

Dr Mustafa Izzuddin is Fellow at ISEAS – Yusof Ishak Institute.  

The facts and views expressed are solely that of the author/authors and do not necessarily reflect that of ISEAS – Yusof Ishak Institute.  No part of this publication may be reproduced in any form without permission.