[2] The college in Delft was a hotbed of student radicalism, and during his time there he joined the Amsterdam chapter of the Social Democratic Workers' Party.
[3] Unlike many European socialists in the Indies, Baars worked hard to learn Malay and Javanese and used this knowledge to involve himself in Indonesian nationalist politics.
[3] Thus in April 1917 he helped found another newspaper, Soeara Merdika (Malay: Voice of freedom) with Semaun, Baars and Noto-Widjojo as editors.
[12] The firing was widely covered in the Dutch press of the Indies; the Bataviaasch Nieuwsblad stated that Baars had defied the Government until his dismissal, so there was no need to feel sorry for him, and that he had in addition made "disgraceful" attacks on the education system in Het Vrije Woord.
[13] However, the Dutch-Indies Teachers' Union (NIOG), in its January 1918 meeting, determined that he had been unfairly fired and proposed to give him financial support, although in the end none was given.
[14] He was eventually offered a municipal engineering job by the mayor of Semarang, who was also a Social Democrat; this enraged the conservative newspapers in the Indies, such as De Preangerbode[16] and Het nieuws van den dag voor Nederlandsch-Indië.
[18] He also helped found an Indonesian socialist group in Surabaya in 1917 called the Sama Rata Hindia Bergerak (Malay: Equality India in Motion) which soon grew to match the ISDV in size.
[6] At the ISDV's annual meeting in May 1920, Baars was present and supported the proposal to rename the party to Perserikatan Kommunist di India (Malay: Communist union in the Indies).
Het Vrije Woord now became the Dutch language organ of the renamed party, with Baars and P. Bergsma as editors, but due to the expulsion of many European socialists from the Indies, it apparently only had 40 subscribers by this time.
In May 1921 the colonial government finally tired of his activities and detained Baars, expelling him from the Indies on the basis of the destabilizing influence of his communist propaganda work.
[28] His recent articles in Het Vrije Woord were also cited as reasons, including one protesting the arrest of a PKI member and another describing the German counter-revolution.
[30] Baars ended up resettling in the Soviet Union with Onok Sawina, becoming an engineer at the Kuzbass Autonomous Industrial Colony in Siberia.
However, the book that caused the greatest stir was his 1928 Sowjet-Rusland in de practijk: Indië tot leering (Dutch: Soviet Russia in Practice: Lessons to India).
[32] These letters he sent to the Indies Dutch press summarizing his book were translated into Malay, Javanese and Sundanese by the government-funded publishing house Kantoor voor de Volkslectuur (Balai Pustaka), in the hopes that it would turn readers away from communism.