Between 1965 and 1966, Indonesia experienced one of the 20th century's most brutal massacres.

History · Published 30 September 2026 Swipe more like this →

In short: Following a failed coup, the Indonesian military and local vigilantes launched a systematic purge of the Communist Party of Indonesia. Estimates suggest between 500,000 and 3 million people were killed in a campaign that reshaped the nation's political landscape and solidified the authoritarian New Order under President Suharto.

The violence began in October 1965, triggered by the 30 September Movement's execution of six top military generals. Major General Suharto, who controlled the strategic reserve, quickly seized power and blamed the Communist Party of Indonesia (PKI) for the coup. While the PKI denied involvement, the military used the event to launch a nationwide anti-communist purge, effectively ending the presidency of Sukarno and the era of his Guided Democracy.

The killings were highly organized, often carried out by military units and civilian militias. In many regions, the military provided lists of suspected communists to death squads. Victims were not limited to PKI members; they included trade unionists, ethnic Chinese, and anyone perceived as a leftist. The violence was often face-to-face, utilizing makeshift weapons like machetes and bamboo spears, with bodies frequently disposed of in rivers. By March 1966, the mass killings had largely subsided, though isolated incidents continued for years.

International involvement played a significant role in the purge. Declassified documents reveal that the United States and the United Kingdom supported the Indonesian authorities, with the U.S. providing lists of PKI officials to death squads and offering economic and military assistance. Western powers viewed the destruction of the PKI as a strategic victory in the Cold War, aiming to prevent the spread of communism in Southeast Asia. Despite the scale of the violence, the events were largely suppressed in Indonesian textbooks for decades.

The legacy of the purge remains deeply embedded in Indonesian society. The New Order regime maintained strict control and a persistent stigma against perceived communist threats, a doctrine that continues to influence political life today. Scholars have struggled to fully explain the frenzy of the violence, which remains a pivotal, yet often overlooked, chapter in modern history.

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