Westerling, born in 1919 in Istanbul, was the son of a Greek mother and a Dutch antique dealer whose family had lived there for three generations. He grew up speaking Greek, Turkish, French and English. In his memoirs he wrote, "One of the few Western European languages that I didn’t speak a word of was my 'mother tongue': Dutch". When the Second World War engulfed Europe in 1941, he went to the Dutch consulate in Istanbul and enlisted in the Dutch army, much to his father’s dismay.
Westerling received his military instruction under the British. In July 1942, he completed his commando training from the Commando Basic Training Center in Achnacarry, Scotland under "Dangerous Dan", a.k.a. William E. Fairbairn. After his promotion to corporal, he became the instructor for "Unarmed Combat" and "Silent Killing" with No. 2 Dutch Troop, 10th Inter-Allied Commando. Within less than a year, Westerling became the instructor for the entire 10th Commando and also instructed "Toughness Training". At his request he left the British Commando staff position and, on December 1943, joined his old No. 2 Dutch Troop in India for Operation Burma. In Ceylon he underwent jungle training, a valuable asset for future assignments. To his disappointment, Westerling was never sent to the front line.
Westerling first came to Indonesia in September 1945, landing in Medan, North Sumatra, as an officer of the KNIL. Conditions there, as in much of Indonesia, were tense and chaotic. Since the end of World War II, the Indonesian people were in an armed and diplomatic struggle against the Dutch to defend their independence. To restore Dutch law and order in Medan, Westerling set up an intelligence network and a police force. In a few months, he had built a reputation for successfully routing those who were branded rogue elements by the Dutch, sometimes using unorthodox methods such as his purge of a gang-leader, who went by the name of Terakan. In his memoirs, he described his action against Terakan, who was responsible for attacks against European and Indonesian civilians in North Sumatra. “We planted a stake in the middle of the village and on it we impaled the head of Terakan. Beneath it we nailed a polite warning to the members of his band that if they persisted in their evildoing, their heads would join his.”
Having completed his first assignment, Westerling took over the DST (Depot Special Forces) commando unit. Westerling's training of his unit was primarily based on his experiences with the British commandos. In September 1946, the DST, stationed at Batavia (modern-day Jakarta), numbered about 130 soldiers, a mix of Dutch war volunteers, Indo-Europeans, and Indonesians. In December 1946, he received the instruction to eliminate the insurgency in southern Sulawesi. Dutch authority in Sulawesi, one of the larger islands of the Indonesian archipelago, was on the verge of an absolute breakdown. Guerilla fighters from Java had joined the local resistance. Hundreds of government officials and members of the pro-Dutch Eurasian and Indo-Chinese community, were attacked and killed. The KNIL garrisons, stationed on the island, were not able to provide protection. Faced with a decay in authority, the Netherlands East Indies government sent Westerling and the DST to end enemy activity by whatever means.
According to Westerling, pacifying Sulawesi without losing thousands of innocent lives could only be accomplished by instituting summary justice, on the spot, for suspected enemy fighters, who were generally executed. This became known as the "Westerling Method". Based on information received from his own informants or the Dutch military intelligence service, the members of the DST surrounded one of more suspected villages during night, after which they drove the population to a central location. At daybreak, the operation began, often led by Westerling. Men would be separated from women and children. From information obtained through spying and intimidation, Westerling exposed certain people as terrorists and murderers. They were shot without any further investigation. Afterwards, Westerling would install a new village leader and set up a village police force. All present would have to swear on the Koran that they would not follow in the path of the “terrorists". Dutch historian Lou de Jong commented in his publication Het Koninkrijk der Nederlanden in de Wereldoorlog on Westerling's action: "There may have been guilty ones among those indicated as having aided the T.R.I.S. or other resistance groups, but surely there were innocent ones among them. Besides that: there was no judicial basis for these summary judicial bloodbaths - even in a state of war they did not exist."
The counter-insurgency operation started in December 1946 and ended in February 1947. While Indonesian authorities claim Westerling was responsible for some 40,000 deaths, most Dutch historians, like Willem IJzereef and Jaap de Moor doubt the veracity of the figure. Mohammed Natzir of the Indonesian Historical Commission of the Armed Forces also calls the figure of 40,000 deaths fiction and a propaganda measure of the Republican government against the Dutch occupation of that time. In his book De Zuid-Celebes Affaire: Kapitein Westerling en de standrechtelijke executies Dutch historian Willem IJzereef claims that the actions of the DST cost about 1,500 Indonesian lives. About 400 of them were executed during actions led by Westerling himself, while the remaining 1,100 were killed during actions of his second in command. Another 1,500 deaths could be added by actions of other KNIL units. Approximately 900 Indonesians were killed by pro-Dutch police units and members of the village police. IJzereef believes that Indonesian resistance caused around 1,500 victims.
Westerling's actions restored Dutch rule in southern Sulawesi.The Indonesian resistance fighters who had not been killed retreated into the mountains and their actions received less cooperation from the locals. However, the Netherlands East Indies government and the Dutch army command soon realised that Westerling's notoriety led to growing public criticism, and there was an official inquiry by the Dutch government in April 1947. Raymond Westerling was put on the sidelines. He was relieved of his duties in November 1948.
Raymond Westerling settled down in western Java, married and started a transportation company. Here he put together an armed movement from groups opposed to the impending transfer of official power from the Dutch to the Indonesian Republic with the aim of preserving the autonomy of the Dutch-created state of Pasundan in western Java. Westerling named his movement the Legion of Ratu Adil (APRA) from the Javanese myth that a messianic figure would come to save the people of Java and establish universal peace and justice.
Supporters were recruited from several social, cultural, and political groups. They were Sundanese who wanted an independent Pasundan not ruled by Javanese, defectors from the Indonesian Republican army, soldiers of the DST and other KNIL units, who opposed the creation of the Indonesian republic. Raymond Westerling claimed that the APRA counted 22,000 men. However, Dutch historian Jaap de Moor says that such an extensive organization only existed in the fantasy of Westerling. On 5 January 1950, Westerling sent an ultimatum to the government of Jakarta. His demands were the recognition of the APRA as the official army of the state of Pasundan and unconditional respect for the autonomy of the federal states. Westerling added that if the answer was not positive, he could not be held responsible for the outbreak of large-scale fighting by the APRA.
With no reply to his ultimatum, Westerling started the coup in the night of 22–23 January, a month after international recognition of the Republic of Indonesia. His plan was to attack Bandung and Jakarta at the same time, concentrating on garrisons, police stations, media centres and other key positions. The APRA would raid and eliminate the Hatta cabinet during one of its government meetings. An interim-federal government, presided over by Sultan Hamid II of Pontianak, would take control. Despite their numerical inferiority to the Siliwangi Division, Westerling's men captured Bandung. However, they failed to take over Jakarta. Law and order were quickly restored by the Republican army and the Indonesian police force. In spite of the coup's relative brevity, it claimed dozens of lives on both sides. While the Dutch government officially condemned the coup, they helped smuggle Westerling out of Indonesia to Singapore.
Via Belgium, Westerling reached the Netherlands, where he settled down with his Indonesian–French wife, Yvonne Fournier, in a small town in the province of Friesland. Westerling later studied singing at the Amsterdam conservatory. His début as a tenor in Puccini’s Tosca in the city of Breda in 1958, however, was a fiasco. Westerling later divorced and remarried. He moved to Amsterdam, where he ran an antique book store. Westerling died of heart failure on November 1987 in Purmerend.
Westerling continued to defend his actions and denied accusations of war crimes. His memoirs devote a chapter to his self-defense. "They painted me as a bloodthirsty monster, who attacked the people of Celebes by fire and sword and exposed all those, who in the interest of Indonesia's national independence resisted Dutch rule, to a merciless campaign of repression". Westerling stated he had based his tactics on the premise that he performed the role of policeman, combating terror: "I arrested terrorists, not because they acted as instigators of the Republican government... but because they made themselves guilty of open and unmistaken crimes...I never had them [his troops] bombard a village, nor did I take the hut of innocent under fire. I had executed some criminals, but nobody had died needlessly or wrongly by my doing.
He was denounced as a war criminal by the Indonesian government and left-wing parties in the Netherlands. Westerling was twice the subject of official inquiries. Dutch historian Nico Schulte Nordholt stated: "...his actions had the tacit approval of the highest authorities, and in the eyes of the Dutch authorities, he was successful at the time. Very cruel, but effective". In 1949, the Dutch–Indonesian agreement on transfer of power stipulated neither country would call the other on its wartime offences, thus ruling out any attempt by Indonesia to press for Westerling's extradition.
In recent years there has been a renewed interest in Raymond Westerling. Dutch movie director Jim Taihutu is to make a film about his actions in southern Sulawesi, while Dutch historian Fredrik Willems announced he is working on a biography about Westerling.