Babrak Karmal befriended fellow inmate Mir Akbar Khyber, who introduced Karmal to Marxism. Karmal changed his name from Sultan Hussein to Babrak Karmal, which means "Comrade of the Workers'" in Pashtun, to disassociate himself from his bourgeois background. When he was released from prison, he continued his activities in the student union, and began to promote Marxism. Karmal spent the rest of the 1950s and the early 1960s becoming involved with Marxist organizations, of which there were at least four in Afghanistan at the time; two of the four were established by Karmal. When the 1964 Afghan Provisional Constitution, which legalised the
Babrak Karmal intervention as an invasion. By 1981, the government gave up on political solutions to the conflict. At the fifth PDPA Central Committee plenum in June, Karmal resigned from his Council of Ministers chairmanship and was replaced by Sultan Ali Keshtmand, while Nur Ahmad Nur was given a bigger role in the Revolutionary Council. This was seen as "base broadening". The previous weight given to non-PDPA members in top positions ceased to be an important matter in the media by June 1981. This was significant, considering that up to five members of the Revolutionary Council were non-PDPA members. By the end