The 30 September 1965 coup attempt (G30S) and the anti-Communist massacres of 1965 to 1966, including the killing of the generals, the role of Suharto, and the destruction of the PKI

What this dot point is asking

NESA expects you to explain the night of 30 September to 1 October 1965, the army's response, the campaign of mass killing that followed across Java, Bali and Sumatra, and the political transition that ended Sukarno's rule and brought Suharto to the presidency. Strong answers integrate the contested causation of G30S, the scale and organisation of the killings (estimated $500\,000$ to $1$ million dead), and the historiography of Robinson, Cribb and Roosa.

The answer

The state of polarisation in 1965

By mid-1965 the army-PKI cleavage was acute. The PKI's "fifth force" demand (PKI Chairman D.N. Aidit, January 1965) called for arming five million workers and peasants alongside the four armed services. The army resisted; the PKI pressed.

The army's strategic reserve (KOSTRAD) was commanded by Major General Suharto; the special forces (RPKAD) by Sarwo Edhie Wibowo; the army headquarters by General Ahmad Yani. Defence Minister and Armed Forces Commander General Nasution sat above them. The PKI claimed three million members and had Sukarno's public support.

Rumours circulated through 1965 of an army "Council of Generals" preparing a coup against Sukarno. The "Gilchrist Letter" (May 1965, attributed to the British ambassador, of contested authenticity) suggested foreign collusion. Sukarno's health failed in August 1965.

The 30 September Movement, night of 30 September to 1 October 1965

Before dawn on 1 October 1965, a unit calling itself the "30 September Movement" (Gerakan 30 September, G30S) under Lieutenant Colonel Untung of the Cakrabirawa palace guard moved to kidnap seven senior army generals. The stated purpose, announced over Radio Republik Indonesia later that morning, was to forestall a "Council of Generals" coup against Sukarno.

Six generals were captured. Yani, Suprapto, Parman, Pandjaitan and Harjono were killed at their homes or on the road; their bodies were taken to Halim Air Base and dumped in a well at Lubang Buaya ("Crocodile Hole"). Brigadier General D.I. Pandjaitan was killed at his home. Lieutenant General Ahmad Yani was killed at his door. General Nasution escaped over a wall; his five-year-old daughter Ade Irma Suryani Nasution and his aide Lieutenant Pierre Tendean were killed in his place.

By 7 a.m. on 1 October 1965 the conspirators held Merdeka Square, RRI, and the telephone exchange. They proclaimed a "Revolutionary Council" by radio.

Suharto's response, 1 to 2 October 1965

Major General Suharto, commander of KOSTRAD, was not on the kidnap list. The standard explanation is that he was not considered politically dangerous; revisionist accounts (Roosa 2006) suggest he had at minimum advance knowledge of the movement.

Suharto assumed command of the army by the morning of 1 October 1965. He sent RPKAD paratroops to recapture RRI and the telephone exchange that afternoon. Halim Air Base was recovered by midnight. The conspirators fled. Lieutenant Colonel Untung was captured in Java in October and executed in 1968.

Sukarno, who had spent the night of 30 September with one of his wives, arrived at Halim during 1 October. Whether he had foreknowledge or sanction remains contested; Roosa (2006) argues that Aidit and Sukarno had at least general knowledge; Anderson and McVey (the "Cornell Paper," 1971) argued G30S was an internal army affair into which the PKI had been drawn.

The anti-Communist campaign

The army, with Suharto in operational command from 1 October, blamed the PKI. The bodies recovered from Lubang Buaya on 4 October 1965 were displayed in army-controlled press with false stories of mutilation by Gerwani women. This propaganda, repeated through the New Order, was foundational to the killings.

From early October 1965, RPKAD paratroops under Sarwo Edhie Wibowo moved into Central Java. Local PKI offices were attacked; PKI members on lists held by the army or by anti-Communist parties (PNI, NU, Masjumi sympathisers, Catholic Party) were arrested or killed. The army systematically organised, trained, and armed Banser (NU), Pemuda Ansor, Pemuda Marhaenis (PNI), and Pemuda Pancasila militias to do the killing.

Central Java fell first, in October to November 1965. East Java followed in November. The Banser militias were central; whole villages of suspected PKI were killed and dumped in rivers. The Brantas and Solo rivers ran with bodies.

Bali, where the PKI had been strong, saw killings in December 1965 to January 1966. Some estimates put the Balinese death toll at 80,000 (around 5 per cent of the island's population). North Sumatra, where the PKI ran plantation unions, saw industrial-scale killing.

Scale and character of the violence

The total death toll is contested. The CIA's 1968 secret history called it "one of the worst mass murders of the 20th century" with 250,000 to 500,000 dead. Robert Cribb's collation (The Indonesian Killings, 1990) estimates around 500,000. The Indonesian National Human Rights Commission and the International People's Tribunal (2015) endorse a figure of up to one million. Conservative scholarly consensus is $500\,000$ to $1$ million dead.

Around 1.5 million Indonesians were detained without trial as "B" or "C" category prisoners, often for many years. Around 10,000 "A" category prisoners were held on Buru Island until 1979. Former detainees were stripped of civil rights, marked on identity cards, and excluded from the public service for decades.

The Supersemar transfer of authority

The killings ran in parallel with a political transition. On 11 March 1966, with armed troops outside the palace at Bogor, three generals (Basuki Rachmat, Amirmachmud, Mohammad Jusuf) obtained from Sukarno a written order (Surat Perintah Sebelas Maret, "Letter of 11 March," Supersemar) authorising Suharto to take "all necessary measures" to restore order.

Suharto used the Supersemar to ban the PKI the next day (12 March 1966), to arrest 15 Sukarnoist ministers (18 March 1966), and to install a new cabinet under his de facto leadership. The original Supersemar document has never been produced; its precise wording remains contested.

On 12 March 1967 the Provisional People's Consultative Assembly (MPRS) revoked Sukarno's mandate and appointed Suharto as acting President. On 27 March 1968 Suharto was formally appointed President. The New Order had begun.

Timeline

Historiography

Geoffrey Robinson (The Killing Season, 2018) treats the killings as state-organised mass murder: army units identified targets, supplied weapons to militias, trained them, and exercised operational control. The decentralised appearance of the killings was deliberate.

Robert Cribb (The Indonesian Killings, 1990) is the standard collation. He stresses regional variation: in some places killings were state-driven, in others they followed communal patterns (NU versus PKI, Balinese caste tensions).

John Roosa (Pretext for Mass Murder, 2006) argues that G30S was a coordinated PKI-Sukarnoist operation drawing on disaffected army officers, but that the killings of the next six months were a separate, far larger campaign organised by Suharto to destroy the party.

Benedict Anderson and Ruth McVey (Cornell Paper, 1971) argued G30S was an internal army affair, with the PKI as bystander. The paper led to the authors' exclusion from Indonesia under the New Order.

Joshua Oppenheimer's films "The Act of Killing" (2012) and "The Look of Silence" (2014) brought New Order impunity into international public attention.

How to read a source on this topic

First, distinguish G30S from the killings. G30S was a 24-hour military action that killed seven army officers and a child. The anti-Communist campaign that followed killed several hundred thousand to a million civilians over six months. The two events have different perpetrators, scales and historiographies.

Second, treat New Order narratives with extreme caution. The Gerwani-mutilation story is propaganda. The "communist threat" justifying mass civilian killing has been documented to be largely retrospective construction.

Third, weigh the documentary record. The CIA's 1968 secret history, the US State Department's 1965-1966 telegrams (declassified 2017), the National Security Archive releases, and the International People's Tribunal Final Report (2016) provide overlapping evidence of state organisation.

Common exam traps

Conflating G30S with the killings. They are two events, six months apart, with different perpetrators and victim profiles.

Treating the killings as spontaneous. Robinson and the declassified record show systematic army organisation. The militias were army-armed and army-trained.

Misdating the Supersemar. 11 March 1966, not 1965 or 1967.

Forgetting the detainees. Around 1.5 million were imprisoned without trial; some held until 1979. Survivors and their families were marked on identity cards until 2004.

In one sentence

The 30 September 1965 coup attempt that killed six senior army generals at Lubang Buaya, the army's six-month anti-Communist campaign that killed an estimated $500\,000$ to $1$ million Indonesians and detained 1.5 million more, and the Supersemar order of 11 March 1966 that transferred authority from Sukarno to Suharto together destroyed the PKI, ended Guided Democracy, and founded the New Order.