Socialist Party of Indonesia

Socialist Party of Indonesia ("Partai Sosialis Indonesia"- PSI) was an Indonesian political party founded by meger of Sutan Sjahrir's "Partai Rakjat Sosialis" (People's Socialist Party) and Amir Sjarifuddin's "Partai Sosialis Indonesia". The party (originally called simply the "Socialist Party", "Partai Sosialis") was a major force at the time of the Indonesian National Revolution. However it was divided into orthodox Marxist 'left-wing' (majority ) and moderate 'right-wing' (minority) factions. The left-wing led by Amir Sjarifuddin (at the time of the merger already a secret communist sympathiser), including the youth league Pesindo, joined the People's Democratic Front led by PKI in 1948. This group was eventually submerged into the PKI. The right-wing led by Sjahrir became the PSI and turned increasingly anticommunist. It was influential in the early 1950s, being especially popular among the college and secondary school students and intellectuals. However, it gradually lost the ground for the PKI, which was growing more and more popular amoing the masses. The Socialist party performed poorly in the 1955 election and was considered a minor party from that time on.

When a rebellion against Sukarno erupted in 1958, and a Revolutionary Government of the Republic of Indonesia (PRRI) was declared on the outer islands, some elements of the PSI, but not Sjahrir himself, supported the coup. On this pretext and for refusing to endorse Sukarno's 'guided democracy', the PSI was banned in 1960.