Brunei–Malaysia border which are defined by agreements, from west to east, are as follows: Brunei and Malaysia in an Exchange of Letters on 16 March 2009, agreed to affirm the five agreements. The two countries also agreed to use the watershed principle to determine the remaining undelimited portions of the border. Brunei's maritime boundary with Malaysia until the 100 fathom isobath was inherited from the Sarawak (Definition of Boundaries) Order in Council 1958 No 1518 and the North Borneo (Definition of Boundaries) Order in Council 1958 No 1517, both of which defined the boundary between Brunei on the one hand, and Sarawak
Indonesia–Malaysia border the assertion that the islands belonged to Malaysia and both countries brought the dispute to the International Court of Justice. In 2002, the court decided that the sovereignty of the two islands belonged to Malaysia. The court however did not determine the maritime boundary in the surrounding waters and specifically decided that the 4° 10' North parallel which marked the easternmost portion of the Indonesia-Malaysia land border in Sebatik island did not extend to sea to form either the territorial sea or continental shelf border. The birth of the Indonesia–Malaysia border, or at least the portion for what is today