First, please note that Malaysia is a kingdom, not a Republic.

President Sukarno was the driving force behind Indonesia’s opposition. His stated concern was the the people of northern Borneo were being included into Malaysia against their will. Broadly speaking, he was correct: the peoples of Borneo were aware that they were likely to be marginalised in the new state. Sukarno was more broadly hostile to Malaya (Malaysia’s predecessor) because its peaceful transition top independence had left both the indigenous aristocracies and British economic interests relatively intact. in. His view, Malaya was a neo-colony whose people were not truly free. Sukarno was also offended by the fact that Britain made its plans for Malaysia without any reference to Indonesia. He believed that he should have been consulted.

Within Indonesia, other forces supported the confrontation with Malaysia. Sections of the army were happy because it gave them greater prominence; other other hand, other sections were deeply opposed because they were aware that they could not win a war with Britain. The communist party was happy to see Confrontation as a means of radicalising the public and getting the best military units out of Java. There was also a hope that Confrontation would provide grounds for creating a ‘fifth force’ of armed peasant militias, who were expected to be sympathetic to the communist cause.

In the end, the course of the conflict did not go well for the Indonesian army and the Confrontation as a whole played into British efforts to demonise Indonesia as an imperial power wanting to annex northern Borneo.