Within both academic historiography and public memory in Western countries, there are particular events of the Cold War that serve as popular markers for how its history is most often discussed and interpreted. Korea, Vietnam, and Afghanistan naturally fill a prominent place in Western discussion because of the overtly spectacular involvement of the two Cold War superpowers, the United States and the Soviet Union. Certainly, these events deserve the attention they have received, given their immense ripple effects and war casualties. However, the popular focus on these events has often obscured other important arenas of the Cold War, arenas that are also historically significant and continue to have a bearing on national and international affairs today.

One such forgotten arena of the Cold War is Indonesia. Indonesia is the fourth most populous country in the world and the largest Muslim-majority country, but its history and significance, broadly speaking, remains obscure for most academics and publics in the West. This is especially true for its pivotal Cold War history during the 1950s and 1960s, when most global attention was naturally drawn towards the American political and military escalations in Vietnam. This same period in Indonesia saw an escalation of socio-political conflict between secular nationalist, Islamist, and Marxist factions within the country tied both to national factors and to the international dimension of the Cold War, with foreign actors covertly involved in the intrigue.

At the height of its power in 1965, the Indonesian Communist Party (PKI) was the largest non-ruling Communist party in the world, thus also making it the third largest Communist party overall after China and the Soviet Union. Yet just a year later, it was officially banned in Indonesia and virtually eradicated through violent purges. The following is the history of its rise and fall.

The Colonial Period

Until 1945, the Indonesian archipelago was the principal colonial possession of the Netherlands and was known as the Dutch East Indies. The earliest iteration of Marxist political organization was the Indies Social Democratic Association (ISDV), founded in 1914 by Dutchman Henk Sneevliet. Sneevliet and other Dutch members of the ISDV supported the October Revolution in Russia and established their own soviets in the Indies in 1917. The colonial government reacted swiftly, however, deporting Sneevliet and most other Dutch ISDV members back to the Netherlands, leaving Marxist activism mostly and covertly in the hands of Indies natives. Native members of the ISDV saw Marxism as an effective way to begin developing a collective anti-colonial/imperial consciousness among the educated native classes of the Indies.

Dutchman Henk Sneevliet (1883–1942), founder of the ISDV, in 1917. Sneevliet would later die in the Amersfoort concentration camp during World War Two.

Another important organization of the period was Sarekat Islam (SI), founded in 1905. SI began as a cooperative of native Javanese Muslim traders of batik, the wax-resist dyed cloth now popularly known as the national cloth of Indonesia. SI eventually opened itself up as a nationalist organization to include educated Muslim activists of various occupations and socio-political persuasions. ISDV members, many nominally Muslim themselves, established their own bloc within SI in 1917. Thus, in these years until 1920, SI was a big tent organization and included secular nationalists, Marxists, and Islamists. However, in 1920, the ISDV changed its name to the Communist Union of the Indies (PKH) and officially joined the Communist International (Comintern). This provoked a negative reaction from SI leaders and members, since its political orientation was nationalist. PKH membership in the Comintern was considered a violation of nationalism, thus during the sixth congress of SI in 1921, the latter voted to oust the PKH bloc.

From that point onward, Marxist politics would carve its own path in Indies-cum-Indonesian history separate from other organizations and movements. In 1924, the PKH underwent its final renaming as the Indonesian Communist Party (PKI). Two years later, through the trade unions it came to control, it attempted an Indies-wide strike, which its more radical members hoped would turn into a total revolution against Dutch colonial rule and the establishment of a Marxist state.

PKI Commissariat Meeting in Batavia (now Jakarta) in 1925. The signage is in Chinese, Jawi (Malay-Arabic script), and Indonesian (Malay creole-Latin script).

However, the Dutch colonial authorities caught wind of these plans and any serious attempt at agitation failed. Subsequently, tens of thousands of natives were arrested, imprisoned or interned, and internally exiled to the far east of the Indies. The PKI went underground and remained so through the rest of the colonial period and the Imperial Japanese occupation of the Indies during World War Two. The PKI would only return to the public sphere in the second half of the 1940s, when the brief interregnum after the Imperial Japanese surrender and before the attempted Dutch colonial return resulted in the birth of the modern Republic of Indonesia.

The War of Independence and the Madiun Affair

Imperial Japan first announced its surrender to the United States on August 15, 1945, signaling the end of World War Two. Subsequently, on August 17, Indonesian nationalists, led by President Sukarno and Vice President Mohammad Hatta of the Indonesian National Party (PNI), proclaimed the independence of the Republic of Indonesia. With this proclamation came the 1945 Constitution, which outlined the hybrid state philosophy of Pancasila (Five Principles). The Principles are as follows: One Lordship, Just and Civilized Humanity, National Unity, Representative Democracy and Consensus, and Social Justice. Debates over the Constitution and the Principles would later define Sukarno’s Presidency, which will be discussed later.

The Dutch, of course, did not accept the proclamation of independence. A four-year War of Independence ensued that saw regular and irregular Indonesian forces battle first British and then Dutch military forces. The War of Independence saw the reconstitution and split of various left-wing factions, some connected to the previous PKI and some not. The previous PKI leadership had remained mostly in exile in the Soviet Union since the 1926 abortive strike. During the first half of the War of Independence, the Socialist Party (PS) broadly represented left-wing factions and included radical Communists and more moderate Fabian Socialists. Sukarno and Hatta integrated the PS into their Cabinet, wanting to present a united front against the Dutch.

Amir Sjarifuddin, radical Marxist Defense Minister (1945–8) and Prime Minister (1947–8). He was executed in 1948 for his role in the Madiun Affair.

A radical member of PS, Amir Sjarifuddin, even served as Defense Minister during 1945–8 and Prime Minister during 1947–8. He also happened to be a secret member of the PKI. Disagreements over a variety of policy issues, notably the Renville Agreement with the Dutch that established a temporary cease-fire, collapsed the Sjarifuddin Cabinet and split the PS into two factions. The moderate Fabian Socialists regrouped as the Socialist Party of Indonesia (PSI), while the radicals under Sjarifuddin regrouped as a new PKI, joining with Musso, an old PKI leader who had returned from exile in 1948.

This breakdown in unity led to armed clashes between PKI and Republican forces in a variety of areas under native control on Java. PKI forces notably seized control in and around the East Java city of Madiun, killing leaders and officials of PNI and Masyumi, a Modernist-Islamist party, in September 1948. It is disputed whether Musso or Sjarifuddin approved of these actions, but in any case they went to Madiun to assume command of the militias. Sukarno and Hatta denounced these actions over the radio and Republican regular forces proceeded to crush the PKI rebellion. This Madiun Affair, as it came to be known, came to an end by December, with PKI forces disarmed and Communist leaders, including Musso and Sjarifuddin, executed.

Remaining PKI leaders went into exile in China, but they were able to return in 1949 at the end of the War of Independence, since Republican leaders decided not to ban the PKI as an organization. The PKI began to rebuild itself successfully in the 1950s under its new Chairman, D.N. Aidit. Whereas its membership in 1950 numbered in the thousands, by 1959 it had 1.5 million members. In the national elections of 1955, it came in fourth place, with 16% of the vote. The fundamental power play between secular nationalists, Marxists, and Islamists had thus been restored in the fully independent Republic of Indonesia and it would come to define the dysfunction and intrigues of the Sukarno Presidency during the 1950s and 1960s.

Sukarno the Puppeteer

Indonesian Presidents, especially those of ethnic Javanese extraction, have often fashioned themselves as Dalang, the master Puppeteers of Javanese shadow puppetry (Wayang Kulit). Sukarno was no exception. He saw his role of Puppeteer as one necessitating the balance between secular nationalist, Islamist, and Marxist factions for the sake of national stability and for his own political benefit and security. National crises and their connections to the global Cold War, however, eventually upset the balancing act, setting the country down a perilous path.

Sukarno (1901–70), first President of Indonesia (1945–67) in 1949.

The mid-1950s saw political gridlock, communal violence, and rebellion. In the Parliament, Masyumi, the Modernist-Islamist party, agitated for a new Constitution enforcing the application of comprehensive Islamic Law on all Indonesian Muslims. Secular nationalists and Marxists naturally opposed this, leading to rancorous debates and public clashes between their supporters. The situation only worsened when some members of Masyumi participated in a rebellion known as PRRI, based in Muslim-majority Sumatra. A separate rebellion, known as Permesta, also erupted in the far east of the country, in the Christian-majority North Sulawesi province. These rebellions became symbolically affiliated because its leaders were regional military commanders dissatisfied with the progress of government decentralization and the failure to pay salary.

After a year of failed negotiations, Sukarno ordered the Indonesian Military to engage the rebels. Engagements lasted a total of three years, but most of that was limited to counter-guerilla operations since the main organs of PRRI-Permesta collapsed soon after the military campaign began. The Cold War dimension of this affair came to light when American pilot Allen Pope was shot down and captured over the city of Ambon, revealing American Central Intelligence Agency (CIA) support for the rebels due to concern over the increasing strength of the PKI.

These events and revelations strengthened Sukarno’s position but also made him increasingly paranoid. In response, he ushered in a new autocratic political system he referred to as Guided Democracy. He disbanded the old Parliament in favor of a new one, to which he appointed half of both the lower and upper houses. He banned Masyumi and the PSI and grew closer to the PKI and its Chairman, Aidit, as a way of balancing against his own secular nationalists in the PNI and the Indonesian Military. In 1960, he went so far as to declare his government to be based on Nasakom, an abbreviation that stood for Nationalism, Religion, and Communism. In 1962, the Parliament declared him President-for-Life.

A PKI supporter wearing a hammer and sickle headdress while attending a PKI rally in 1955.

Abroad, this naturally garnered the further negative attention of the United States and the United Kingdom. Both were concerned that Indonesia could be the next country to become Communist. At this point, the PKI claimed 3 million members. Domestically, secular nationalists, especially in the Indonesian Military, harbored the same fears. Many officers were fervently anti-Communist, shaped both by nationalist philosophy and the Madiun Affair. Some sections of the Military, however, were sympathetic to aspects of PKI foreign policy and economic goals, even if not supportive of Marxism itself. Broader sections of the Indonesian public also resented the influence of the PKI. Tensions worsened when Aidit called for a “fifth armed force” of peasants and labor and Sukarno declared an “Axis” of Asian Marxist entities. These machinations finally came to a head in September 1965 and the country would be forever changed.

The September 30 Movement

Overnight on September 30, 1965, select units of the Presidential Guard and the Army’s East and Central Java Divisions set out in the capital city of Jakarta to kidnap seven prominent Army Generals. Three of the Generals were killed in their homes. Three were kidnapped and later executed outside Jakarta. However, the most important target, Minister of Defense and Supreme Commander A.H. Nasution, escaped his home and fled to the Iraqi Embassy next door, severely injuring his leg as he leapt over the dividing wall. What is bizarre is that the perpetrators were clearly unprepared and ignorant, for they kidnapped Nasution’s adjutant, First Lieutenant Pierre Tendean, when he bravely claimed that he was Nasution. Tendean was later executed, too.

The next day, on October 1, these Army units seized key offices and communication apparatuses around Freedom Square, a centrally strategic area in Jakarta that includes the Presidential Palace. They announced themselves as the September 30 Movement (G30S) over the radio, claiming that they were preventing a right-wing CIA coup against Sukarno by a so-called Council of Generals, referring to the senior officers they had targeted. The nature of the G30S occupation of Freedom Square is one of many facts that have given rise to conspiracy theories about this history. For unclear and nonsensical reasons, G30S did not occupy the eastern side of the Square. That side was home to KOSTRAD, the Army Strategic Reserve, the seizure of which would have been essential to G30S’s success. Conspiracy theories are thus fueled because of the identity of KOSTRAD’s commanding officer, a relatively young Major General named Suharto.

Once news broke of G30S, Suharto rushed to his command at KOSTRAD with the intent of restoring unified control over the Army and dismantling G30S. Beyond Freedom Square, other units of G30S were principally based at Halim Perdanakusuma International Airport in South Jakarta. Overnight, as the Generals were killed, Sukarno, PKI Chairman Aidit, and even the Commander of the Air Force, Air Marshal Omar Dani, went to Halim Airport, clearly under the protection of G30S. When Dani’s presence was exposed, it horrified the remainder of the Air Force senior staff, who had previously agreed with one another to remain uninvolved in Army/PKI intrigues. Vice Air Marshal Makki Perdanakusuma (incidentally the brother of the airport’s namesake), dispatched a letter to Suharto, declaring that Dani did not have any support from the Air Force. According to the courier, Suharto glanced at the letter and then tore it up, dismissively saying, “this means nothing to me.”

By the end of October 1, just one day after G30S started, Aidit fled to Central Java and Dani to East Java, prompted by the G30S units in Jakarta surrendering without a fight to a conciliatory Suharto. The latter urged reunification in order to go after the “real” enemy, the PKI. Concurrently, Sukarno left Halim Airport for the Presidential Palace in Bogor, West Java, where he was confined by Suharto allies and compelled to sign the Supersemar, a decree granting broad powers to Suharto to restore stability. Suharto’s rhetoric on Sukarno was manipulatively measured through this affair. Suharto consistently declared that all of his actions were in the name of protecting Sukarno. However, Suharto used the presence of Dani, Aidit, and Sukarno at Halim Airport to discredit the Air Force, to push for the destruction of the PKI, and to allow elites and the public to rally against Sukarno, who was seen as complicit in, and responsible for, the chaos.

D.N. Aidit (1923–65), PKI Chairman (~1950–65), in an undated photo.

For obvious reasons, the historical truths of G30S are thoroughly debated among Indonesians and foreign Indonesianists. What can be firmly stipulated, however, is that G30S was fundamentally an internal Army affair that utilized, and was subsumed by, the larger struggles between Indonesian political factions and external actors in the global Cold War. Whether or not Suharto was aware of, or involved in, the G30S plan beforehand cannot be proven beyond conspiracy theories. What is apparent is that he suavely and brilliantly took advantage of the situation for his own purposes, personally and politically. Notwithstanding some Army units in Java and Bali that fought Suharto’s reunified command, Suharto turned the fight principally against the PKI. Yet this national campaign against the PKI also devolved into horizontal violence between socio-economic and religious groups and between individuals settling social scores.

The Peculiar Divides of Indonesian Islam

It is important to first qualify some of the constituencies that lent support and opposition to the PKI, as this will clarify the horizontal violence following G30S that ensued between average Indonesians during 1965–6. One factor is the division within Indonesian Islam, the majority-religion of the country. Indonesian Islam can be most basically divided into two groups: the Santri, who are both Traditionalist and Modernist scripturalists, and the Abangan, syncretic Muslims who also adhere to some pre-Islamic Hindu, Buddhist, and animist traditions.

Although the PKI was officially atheist, it did not require its members to be. Thus, it drew much support from the Abangan, both because of their flexible religious orientation and because they tended to be more economically destitute as part of the old peasant class. Conversely, the Santri were fiercely opposed to the PKI, both because of its atheism and also because Traditionalist Santri tended to be landowners and power brokers within Javanese society. The Abangan-Santri divide had also partially defined the Madiun Affair, with Abangan PKI militias attacking Santri leaders and officials. This socio-religious-economic division among the laity, along with the elite tensions between nationalists and most of the military on one side and the PKI and Sukarno on the other, led to the horrific yearlong national eruption of violence that followed G30S.

The Year of Living Dangerously

Following G30S, the Army used intelligence provided by the American CIA and British Foreign Office to hunt down PKI members. The American Government further provided economic and technical aid to the Army. By November 1965, Aidit was captured and executed, while Dani was court-martialed and imprisoned until receiving a pardon in 1995. Beyond official military engagements, the Army knowingly used organized crime and paramilitaries of the two largest Santri Islamic organizations, Nahdlatul Ulama (NU) and Muhammadiyah, to root out local PKI members. Those killed in the ensuing violence during 1965–6, however, were not all PKI. Some victims were found guilty-by-association or killed in cases of mistaken identity. The numbers vary and may never be properly determined, but it is estimated that the victims of regular and irregular anti-Communist forces is somewhere between half a million and two million Indonesians during this period.

As the PKI was strongest in Central Java, East Java, and Bali, the effect of this violence in these provinces cannot be overstated. The killings were so widespread and so swift that government officials complained to the Army that bodies were clogging local Javanese rivers. Santri leaders called upon the memory of the Madiun Affair and its Abangan-on-Santri violence to now justify Santri-on-Abangan violence. In Hindu-majority Bali, where the PKI had challenged the caste system and elite caste landownership, traditionalist elites called upon all Balinese to protect Hindu identity and culture by destroying the PKI. It is estimated that 5% of the island’s population was killed, the highest proportion of killings in the whole country by province. Due to the PKI’s close relationship to the People’s Republic of China, violence was also instigated throughout the country against ethnic-Chinese, even though most were not PKI supporters.

Left and Right: Sukarno and Suharto in February 1967, during the handover of power that made Suharto acting President.

In February 1967, under threat of impeachment, Sukarno resigned the Presidency and was placed under house arrest in the Bogor Palace. Suharto was immediately named acting President and was later officially elected President in March 1968 by the Parliament. Sukarno would die in 1970 from kidney failure, after being denied medical care. Suharto would continue to rule his regime, known as the New Order, until 1998, when the Asian Financial Crisis of 1997–8 provoked unrest that motivated Indonesian elites, including in the Army, to abandon their support for Suharto. He was forced to resign, which ushered in the Reformation era of liberalization and democratization.

Unexpected Legacies

In terms of the global Cold War, this violent set of events in Indonesia represented a major victory for anti-Communist forces. However, due to the covert nature of foreign involvement, this was a victory that could not be publicly acknowledged in the West for decades. It is tragically ironic on several fronts, considering that this period was the beginning of escalation in Indo-China and the consequent skepticism on the Western role in the Cold War.

The nature of the killings in 1965–6 also created unexpected consequences for Indonesian religion at both the elite and lay levels. For those in the Abangan populace who were caught in the violence or having to flee it, many were deeply resentful of the Santri and other elite authorities. All Indonesian citizens were required to formally register as adherents of one of five official religions: Islam, Protestantism, Catholicism, Hinduism, or Buddhism. The need to blend in and survive during a time of national hysteria and violence meant religious conversion in many cases, but the specificities of conversion often manifested purely by circumstantial convenience.

Some Javanese Abangan feigned rebirth as Santri, while others converted to either Protestantism or Catholicism. However, if Abangan PKI sympathizers from Java, regardless of faith, happened to be in Bali during 1965–6, they converted to Balinese Hinduism. There are, thus, documented cases of sectionalized Javanese Abangan families that partly converted to Christianity because they were on Java and partly converted to Hinduism because they were on Bali. These families remain religiously split even after the Reformation as a matter of inertia and subsequently earnest religious commitment.

The actions of Masyumi in the 1950s and other Islamic groups in the 1960s horrified a particular group of Modernist Santri Muslims. This group became what is known historiographically as the Renewal of Islamic Thought, the most important Muslim movement of the 20th Century to depoliticize and reform Islam. Parallel to this was a hardening of other Santri identities and the suppression of Abangan political mobilization or any mobilization deemed Leftist or atheist.

President Suharto and First Lady Tien practicing at a gun range in 1967, while their son, Tommy, looks on.

During his Presidency, Suharto banned the PKI and made anti-atheism an integral part of his New Order, primarily through instituting a law against blasphemy. Although serving a mostly symbolic purpose during his New Order, the post-Suharto Reformation has seen Islamist groups use and abuse the blasphemy law to target non-Muslim minorities and heterodox Muslims. Thus, the blasphemy law and the de-liberalization of Indonesian society during the New Order and the Cold War fight against Communism are directly connected to the disproportionately manipulative strength of Indonesian Islamism today. The hardening of religious identities, especially Islamic, combined with the blasphemy law make the religious landscape more chauvinistic in a now liberalized environment than it would have been otherwise.