As a part of its withdrawal from its Southeast Asian colonies, the UK moved to combine its colonies in North Borneo with the Federation of Malaya (which had become independent from Britain in 1957), and Singapore (which had become self-governing in 1959). In May 1961, the UK and Malayan governments proposed a larger federation called Malaysia, encompassing the states of Malaya, North Borneo, Sarawak, Brunei, and Singapore. Initially, Indonesia was mildly supportive of the proposed federation, although the PKI (Partai Komunis Indonesia — Indonesian Communist Party) was firmly opposed to it. In Brunei, it was unclear whether the Sultan Omar Ali Saifuddien III would support Brunei joining the proposed Malaysian state because of the implied reduction of his political office, and Brunei's oil revenues ensured Brunei's financial viability were it to choose independence. Furthermore, a Brunei politician, Dr. AM Azahari bin Sheikh Mahmud, while supporting a unified North Borneo, also opposed a wider Malaysian federation. In 1961, he had sounded out Indonesia about possible aid in training Borneo recruits; General Abdul Nasution hinted at moral support, and Soebandrio, the Indonesian foreign minister and head of intelligence, hinted at supplying more substantial aid. Azahari was a leftist who had fought in Indonesia in their war for independence. Following these meetings, Indonesia began training in Kalimantan a small volunteer force, the North Kalimantan National Army (TNKU). On 8 December 1962, the TNKU staged an insurrection—the Brunei Revolt. The insurrection was an abject failure, the poorly trained and equipped forces were unable to seize key objectives such as capturing the Sultan of Brunei, seize the Brunei oil fields, or take European hostages. Within hours of the insurrection being launched, British forces based in Singapore were being mobilised for a prompt response. The failure of the insurrection was evident within 30 hours when Gurkha troops airlifted from Singapore secured Brunei town and ensured the Sultan's safety. The degree of Indonesian support for the TNKU remains a subject of debate. While Indonesia at the time denied direct involvement, it did sympathise with the TNKU's objectives to destabilise the proposed Malaysian state. Following the TNKU's military setback in Brunei, on 20 January 1963 Indonesian Foreign Minister Subandrio announced that Indonesia would pursue a policy of "Konfrontasi" with Malaysia, reversing Indonesia's previous policy of compliance with the British proposal.