Alongside other young politically active journalists such as Sanusi Pane and Adam Malik, they founded the Antara news agency[5] which derived its name from Perantaraan.

[7] During the Japanese occupation of the Dutch East Indies, Soemanang worked in the Japanese-founded Asia Raya newspaper and later headed the press department of the labor organization PUTERA [id].

[3] Another incident close to the end of the war saw Soemanang arrested for another image of Hirohito stained by red ink from the flag and resulted in the Japanese authorities forcing Pemandangan to be published as Pembangoenan.

[3] Shortly after the proclamation of Indonesian independence, Sumanang co-founded the National Press Company (Badan Usaha Penerbitan Nasional).

[15] One of his policies was to return the oil wells in North Sumatra back to the control of Royal Dutch Shell, which faced fierce criticism from the parliament and he withdrew this decision.

[16] Additionally, alongside Interior Minister Mohammad Roem, Soemanang ordered the issuance of 50 million identity cards for registry purposes.

[1] He also served as an executive director in the International Monetary Fund for some time, representing Indonesia, Algeria, Ghana, Laos, Libya, Morocco a Tunisia.