Indonesia–Malaysia confrontation of the action occurring in the border area between Indonesia and East Malaysia on the island of Borneo (known as Kalimantan in Indonesia). The conflict was characterised by restrained and isolated ground combat, set within tactics of low-level brinkmanship. Combat was usually conducted by company- or platoon-sized operations on either side of the border. Indonesia's campaign of infiltrations into Borneo sought to exploit the ethnic and religious diversity in Sabah and Sarawak compared to that of Malaya and Singapore, with the intent of unraveling the proposed state of Malaysia. The challenging jungle terrain of Borneo and lack of roads straddling
Brunei–Malaysia border and Sabah, Malaysia, on the other. All three territories were then ruled by Britain. The powers for the order in council were derived from the British Colonial Boundaries Act of 1895. Brunei and Malaysia still adhere to the British Orders in Council to define their territorial waters, where it was referred to in the Joint Statement made after the 18th Annual Leaders' Consultation between the Sultan of Brunei and Prime Minister of Malaysia on 3 November 2014 when reference was made to the Sarawak (Definition of Boundaries) Order in Council 1958 No 1518 as part of the boundary definition process