Within the next few years, bureaucratic centralism under the direction of KSČ leadership was introduced. So-called "dissident" elements were purged from all levels of society, including the Catholic Church. The ideological principles of Marxism-Leninism and pervaded cultural and intellectual life. The entire education system was submitted to state control. With the elimination of private ownership of means of production, a planned economy was introduced. Czechoslovakia became a satellite state of the Soviet Union; it was a founding member of the Council for Mutual Economic Assistance (Comecon) in 1949 and of the Warsaw Pact in 1955. The attainment of Soviet-style "socialism" became the government's avowed policy.