Indonesia–Malaysia confrontation in the context of "Cold War in Asia"

From October of 1965 to March of 1966, a series of large-scale killings and civil unrest primarily targeting members and supposed sympathizers of the Communist Party of Indonesia (PKI) were carried out in Indonesia. Other affected groups included alleged communist sympathisers, Gerwani women, trade unionists, ethnic Javanese Abangan, ethnic Chinese, atheists, accused "kafir" (unbelievers in Islam), and alleged leftists in general. According to the most widely published estimates, at least 500,000 to 1 million people were killed. Some of the higher estimates reach figures as much as 2 to 3 million. The atrocities, sometimes described as a genocide or a politicide, were instigated by the Indonesian Army under Suharto. Research and declassified documents demonstrate the Indonesian authorities received support from foreign countries such as the United States and the United Kingdom.

The killings began as an anti-communist purge following a so-called attempted coup d'état by the 30 September Movement. It was a pivotal event in the transition to the "New Order" and the elimination of PKI as a political force, with impacts on the global Cold War. The Army, after banning all independent news source from issuing for a week, almost at once pinned the abortive coup attempt to the PKI. Additionally, the intelligence agencies of the United States, United Kingdom and Australia engaged in black propaganda campaigns against Indonesian communists. During the Cold War, the U.S., its government, and its Western allies had the goal of halting the spread of communism and bringing countries into the sphere of Western Bloc influence. Britain had additional reasons for seeking Sukarno's removal, as his government was involved in an undeclared war with neighbouring Malaysia, a Commonwealth federation of former British colonies.

Sarawak (/səˈrɑːwɒk/ sə-RAH-wok, Malay: [saˈrawaʔ]) is a state of Malaysia. It is the largest among the 13 states, with an area almost equal to that of Peninsular Malaysia. Sarawak is located in East Malaysia in northwest Borneo, and is bordered by the Malaysian state of Sabah to the northeast, Kalimantan (the Indonesian portion of Borneo) to the south, and Brunei in the north. The state capital, Kuching, is the largest city in Sarawak, the economic centre of the state, and the seat of the Sarawak state government. Other cities and towns in Sarawak include Miri, Sibu, and Bintulu. As of 2020 Malaysia census, the population of Sarawak was 2.453 million. Sarawak has an equatorial climate with tropical rainforests and abundant animal and plant species. It has several prominent cave systems at Gunung Mulu National Park. Rajang River is the longest river in Malaysia; Bakun Dam, one of the largest dams in Southeast Asia, is located on one of its tributaries, the Balui River. Mount Murud is the highest point in the state. Sarawak is the only state of Malaysia with a Christian majority.

The earliest known human settlement in Sarawak at the Niah Caves dates back 40,000 years. A series of Chinese ceramics dated from the 8th to 13th century AD was uncovered at the archaeological site of Santubong. The coastal regions of Sarawak came under the influence of the Bruneian Empire in the 16th century. In 1839, James Brooke, a British explorer, arrived in Sarawak. He, and his descendants, governed the state from 1841 to 1946. During World War II, it was occupied by the Japanese for three years. After the war, the last White Rajah, Charles Vyner Brooke, ceded Sarawak to Britain, and in 1946 it became a British Crown Colony. On 22 July 1963, Sarawak was granted self-government by the British and subsequently became one of the founding members of Malaysia, established on 16 September 1963. However, the federation was opposed by Indonesia, leading to a three-year confrontation. The creation of Malaysia also prompted a communist insurgency that lasted until 1990.

Sabah (Malay pronunciation: [ˈsabah]) is a state of Malaysia located in northern Borneo, in the region of East Malaysia. Sabah has land borders with the Malaysian state of Sarawak to the southwest and Indonesia's North Kalimantan province to the south. The Federal Territory of Labuan is an island just off Sabah's west coast. Sabah shares maritime borders with Vietnam to the west and the Philippines to the north and east. Kota Kinabalu is the state capital and the economic centre of the state, and the seat of the Sabah State government. Other major towns in Sabah include Sandakan and Tawau. The 2020 census recorded a population of 3,418,785 in the state. It has an equatorial climate with tropical rainforests, abundant with animal and plant species. The state has long mountain ranges on the west side which forms part of the Crocker Range National Park. Kinabatangan River, the second longest river in Malaysia runs through Sabah. The highest point of Sabah, Mount Kinabalu is also the highest point of Malaysia.

The earliest human settlement in Sabah can be traced back to 20,000–30,000 years ago along the Darvel Bay area at the Madai-Baturong caves. The state has had a trading relationship with China starting from the 14th century AD. Sabah came under the influence of the Bruneian Empire in the 14th and 15th centuries. The state was subsequently acquired by the British North Borneo Chartered Company in the 19th century. During World War II, North Borneo was occupied by the Japanese for three years. It became a British Crown Colony in 1946. On 31 August 1963, the newly-renamed Sabah was granted self-governance by the British. Following this, Sabah became one of the founding members of the Federation of Malaysia (established on 16 September 1963) alongside the Crown Colony of Sarawak, the Colony of Singapore (expelled in 1965), and the Federation of Malaya (Peninsular Malaysia or West Malaysia). The federation was opposed by neighbouring Indonesia, which led to the Indonesia–Malaysia confrontation over three years along with the threats of annexation by the Philippines along with the Sultanate of Sulu, threats which continue to the present day.

The Indonesian Army (Indonesian: Tentara Nasional Indonesia Angkatan Darat (TNI-AD), lit. 'Indonesian National Military-Land Force') is the land branch of the Indonesian National Armed Forces. It has an estimated strength of 300,400 active personnel. The history of the Indonesian Army has its roots in 1945 when the Tentara Keamanan Rakyat (TKR) "People's Security Army" first emerged as a paramilitary and police corps.

Since the nation's independence movement, the Indonesian Army has been involved in multifaceted operations ranging from the incorporation of Western New Guinea, the Indonesia–Malaysia confrontation, to the annexation of East Timor, as well as internal counter-insurgency operations in Aceh, Maluku, and Papua. The army's operations have not been without controversy; it has been periodically associated with human rights violations, particularly in West Papua, East Timor, and Aceh.

The communist insurgency in Sarawak was an insurgency in Malaysia from 1962 to 1990, and involved the North Kalimantan Communist Party (NKCP) and the Malaysian Government. It was one of the two communist insurgencies to challenge the former British colony of Malaysia during the Cold War. As with the earlier Malayan Emergency (1948–1960), the communist insurgents in Sarawak were predominantly ethnic Chinese, who opposed British rule over Sarawak and later opposed the merger of the state into the newly created Federation of Malaysia. The insurgency was triggered by the 1962 Brunei revolt, which had been instigated by the left-wing Brunei People's Party in opposition to the proposed formation of Malaysia.

The communist insurgents in Sarawak were also supported by Indonesia until 1965, when the pro-Western president Suharto assumed power in a coup and ended the confrontation with Malaysia. During that period, the NKCP's two main military formations were created: the Sarawak People's Guerrilla Force (SPGF) or Pasukan Gerilya Rakyat Sarawak (PGRS), and the North Kalimantan People's Army (NKPA) or the Pasukan Rakyat Kalimantan Utara (PARAKU). Following the end of the confrontation, Indonesian military forces would co-operate with the Malaysians in counter-insurgency operations against their former allies.

Tawau (Malaysian: [ˈta wau]), formerly known as Tawao, is the capital of the Tawau District in Sabah, Malaysia. It is the third-largest city (or town) in Sabah, after Kota Kinabalu and Sandakan. It is located on the Semporna Peninsula in the southeast coast of the state in the administrative centre of Tawau Division, which is bordered by the Sulu Sea to the east, the Celebes Sea to the south at Cowie Bay and shares a border with North Kalimantan, Indonesia. The town had an estimated population as of 2010, of 113,809, while the whole municipality area had a population of 397,673 (including 47,466 in Kalabakan, subsequently split off to form a separate district). The municipal area had a population of 372,615 at the 2020 Census.

Before the founding of Tawau, the region around it was the subject of dispute between the British and Dutch spheres of influence. In 1893, the first British merchant vessel sailed into Tawau, marking the opening of the town's seaport. In 1898, the British set up a settlement in Tawau. The North Borneo Chartered Company (BNBC) accelerated growth of the settlement's population by encouraging the immigration of Chinese. Consequent to the Japanese occupation of North Borneo, the Allied forces bombed the town in mid-1944, razing it to the ground. After the Japanese surrender in 1945, 2,900 Japanese soldiers in Tawau became prisoners of war and were transferred to Jesselton. Tawau was rebuilt after the war, and by the end of 1947, the economy was restored to its pre-war status. Tawau was also the main point of conflict during the Indonesia–Malaysia confrontation from 1963 to 1966. During that period, it was garrisoned by the British Special Boat Section, and guarded by Australian Destroyers and combat aircraft. In December 1963, Tawau was bombed twice by Indonesia and shootings occurred across the Tawau-Sebatik Island international border. Indonesians were found trying to poison the town's water supply. In January 1965, a curfew was imposed to prevent Indonesian attackers from making contact with Indonesians living in the town. While in June 1965, another attempted invasion by the Indonesian forces was repelled by bombardment by an Australian destroyer. Military conflict finally ended in December 1966.

The Brunei revolt (Malay: Pemberontakan Brunei) or the Brunei rebellion of 1962 was a December 1962 insurrection in the British protectorate of Brunei by opponents of its monarchy's proposed inclusion in the Federation of Malaysia. The insurgents were members of the TNKU (North Kalimantan National Army), a militia supplied by Indonesia and linked to the left-wing Brunei People's Party, which favoured a North Borneo Federation. The TNKU began co-ordinated attacks on the oil town of Seria (targeting the Royal Dutch Shell oil installations), on police stations, and on government facilities around the protectorate. The revolt began to break down within hours, having failed to achieve key objectives such as the capture of Brunei Town and Sultan Omar Ali Saifuddien III. The revolt influenced the Sultan's 1963 decision not to join Malaysia. It is seen as one of the first stages of the Indonesia–Malaysia confrontation.