Indonesia–Malaysia confrontation party which was founded in June 1959. The Sarawak Insurgency began after the Brunei Revolt in 1962 and SCO would fight alongside the Bruneian rebels and Indonesian forces during the Indonesia–Malaysia confrontation (1963–1966). The Sarawak Communist Organisation and the Bruneian rebels supported and propagated the unification of all British Borneo territories to form an independent leftist North Kalimantan state. This idea was originally proposed by A. M. Azahari, leader of the Parti Rakyat Brunei (Brunei People's Party), who had forged links with Sukarno's nationalist movement, together with Ahmad Zaidi, in Java in the 1940s. However, the Brunei People's Party was
Indonesia–Malaysia border dispute originated in 1969 when the two countries negotiated to delimit the common border of their continental shelf. As the two countries could not agree on the soveignty of the two islands, the continental shelf border was left off the 1969 agreement between the two countries. Indonesia claimed that the islands were theirs by virtue of the fact that they were located south of 4° 10" North which it said formed the maritime border between it and Malaysia by virtue of a straight line extension of the land border which ended on the east coast Sebatik island. Malaysia however, claimed