Following its swift victory in the Dutch East Indies campaign of 1941–1942, Imperial Japan was welcomed as a liberator by much of the native population of the Dutch East Indies (present-day Indonesia),[14][15] and especially by the Indonesian nationalists who since the early 20th century had begun developing a national consciousness.[16][17] In the wake of the Japanese advance, rebellious Indonesians across the archipelago killed scores of European and pro-Dutch civilians (in particular from the Chinese community)[18] and informed the invaders on the whereabouts of others,[19] 100,000 of whom would be imprisoned in Japanese-run internment camps alongside 80,000 American, British, Dutch, and Australian prisoners of war.[20] Unlike in occupied French Indochina, where Imperial Japan worked alongside the French colonizer, the Japanese supplanted the Dutch administration of the East Indies and elevated native elites willing to work with them to power,[21] fueling Indonesian hopes of future self-rule.[20] Imperial Japan imposed a strict occupation regime on the archipelago, however, as to them the value of the archipelago lay mostly in its ample resources for the war effort (specifically oil, tin, and bauxite) and their initial use for the nationalists only extended to the pacification and organization of the sizeable population of Java.
During the occupation of the Dutch East Indies, Sukarno and Mohammad Hatta, respectively the inaugural president and vice president of the future Republic of Indonesia, became promoters of the Japanese rōmusha forced labor scheme through the Center of the People's Power (Pusat Tenaga Rakyat; Putera) and mobilized workers for Japanese production and construction projects across Southeast Asia, such as the strategic railways on Sumatra and West Java, and along the Burma–Thailand border. In total, 4 to 10 million Indonesian laborers were recruited and some 270,000 to 500,000 Javanese were sent abroad, of whom 70,000 to 135,000 returned after the war. In November 1943, the Japanese flew Sukarno and Hatta to Tokyo to receive the Order of the Rising Sun from Emperor Hirohito for their services. Similarly, Indonesia's second president Suharto and first commander of the Indonesian National Armed Forces Sudirman began their military careers in the Japanese-sponsored Defenders of the Homeland (Pembela Tanah Air; PETA), which alongside the auxiliaries of the Heiho (兵補) was to assist the Imperial Japanese military in fighting off the expected Allied return to the East Indies. Hundreds of thousands served in Japanese organizations such as the propaganda institution Keimin Bunka Shidōsho (啓民文化指導所), the youth movement Seinendan (青年団), and the auxiliary police forces of the Keibōdan (警防団).
As its fortunes turned, Imperial Japan became faced with growing resistance to its increasingly repressive occupation and began catering to the Indonesian desire for self-rule. Already in September 1943, the Javanese Central Advisory Council (Chūō Sangiin, 中央参議院) had been created around Sukarno, Hatta, Ki Hajar Dewantara, and Mas Mansur, and expanded to include notables such as Rajiman Wediodiningrat and Ki Bagus Hadikusumo.[30] Sumatran representation under Mohammad Syafei, Abdul Abas, and Teuku Nyak Arif would follow nearly two years later and included established nationalists such as Djamaluddin Adinegoro and Adnan Kapau Gani.[31] In January 1944, the Center of the People's Power was replaced by the less overtly Japanese-controlled Hōkōkai (奉公会; Himpunan Kebaktian Rakjat) in a renewed attempt to increase Javanese labor and produce for the Japanese war effort.[32] A paramilitary youth wing, the Suishintai (推進体; Barisan Pelopor), would be founded in August.[33] In July 1944, Japanese prime minister Hideki Tojo was forced to resign and on 7 September his replacement Kuniaki Koiso made a promise of independence for "the East Indies" di kemudian hari (English: at a later date).
In spite of the deteriorating military situation and a disastrous famine on Java, war enthusiasm had returned to the extent that the suicide attack corps Jibakutai (自爆隊; Barisan Berani Mati) could be formed on 8 December 1944.
On 14 February 1945, a PETA battalion under Supriyadi launched a short-lived revolt against the Japanese in Blitar, East Java. Although it was quickly put down and possibly misattributed to nationalist fervorit factored into the Japanese realization that their window on creating an Indonesian puppet state had closed.
Hoping to extend the occupation by redirecting nationalist energy towards harmless political squabbles, the military authority on Java announced the formation of the Investigating Committee for Preparatory Work for Independence (Badan Penyelidik Usaha-usaha Persiapan Kemerdekaan; BPUPK) on 1 March 1945.[39] Despite meeting only twice, the plenary sessions of the BPUPK would see the formulation of Pancasila and the Jakarta Charter that would later form the basis of the preamble to the Constitution of Indonesia.[40] On 7 August, the day after the atomic bombing of Hiroshima, Japanese field marshal Hisaichi Terauchi approved the establishment of the Preparatory Committee for Indonesian Independence (Panitia Persiapan Kemerdekaan Indonesia; PPKI) and promised Indonesian independence would be granted on 24 August 1945.[ As Imperial Japan surrendered to the Allies on 15 August, Sukarno instead proclaimed Indonesian independence on 17 August 1945. In the Indonesian National Revolution that followed, 903 Japanese nationals volunteered for the Indonesian cause, of whom 531 wound up dead or missing.
