Indonesia–Malaysia border Indonesia–Malaysia border The border between the Southeast Asian countries of Indonesia and Malaysia consist of both a land border separating the two countries' territories on the island of Borneo as well as maritime boundaries along the length of the Straits of Malacca, in the South China Sea and in the Celebes Sea. The land boundary has a length of 2,019.5 km and stretches from Tanjung Datu at the northwestern corner of Borneo, through the highlands of the Borneo hinterland, to the Gulf of Sebatik and the Celebes Sea in the eastern side of the island. The boundary separates the Indonesian
Brunei–Malaysia border World War II, joined Malaysia on 16 September 1963. Brunei remained a British Protectorate until 1984 when it gained independence. Brunei and Malaysia have had long standing disputes over land and maritime territories. However, due to the cultural ties between the two countries, the disputes have always been low-key and deemed too sensitive to be discussed openly. The main land dispute was over the district of Limbang which has been controlled by Sarawak since 1890, while the dispute over maritime territory involved virtually the entire deep sea section of the South China Sea claimed by Brunei which Malaysia asserted as