Arif Havas Oegroseno is Indonesia’s Ambassador to Belgium, Luxembourg and the EU, and President of the 20th Meeting of the States Parties of United Nations Convention on the Law of the Sea (UNCLOS) 1982:
There are two important lessons arising from the negotiations between Indonesia and the Philippines over their bilateral maritime boundaries. Firstly, whether you like it or not, the current prevailing law to settle maritime boundaries is UNCLOS. This is true regardless of your historical record, even if it is 115 years old. If a rectangular line map from a century-old Treaty had to be aligned with UNCLOS, aligning a dash-line map that was created only in the mid-1940s with UNCLOS should be relatively problem-free. While there is a difference in shape between the rectangular line of the Treaty of Paris that the Philippines previously used with Indonesia, and the nine dash-line map that China currently bases its maritime claims in the South China Sea on, they share one similarity: both are unilateral expressions of claims that are not based on international law. The first Indonesia-Philippines maritime boundary signifies the emergence of a state practice whereby in a maritime boundary dispute a unilateral proclamation of maps will eventually be aligned with prevailing international law. Secondly, the claimants need not look far to see how countries in the region can work together for the larger interest over a large swath of waters devoid of maritime boundaries…..It is my conviction that all claimant states in the South China Sea, especially China, which is also a Permanent Member of the UN Security Council, carry the moral, political, and legal responsibility of creating peace and stability in the world and are able to work together peacefully.
Read more at How Indonesia and the Philippines Solved Their Maritime Dispute | The Diplomat.