The state security police ( the KGB and its predecessor agencies ) played an important role in Soviet politics . It was instrumental in the Stalinist terror , but after the death of Stalin , the state security police was brought under strict party control . Under Yuri Andropov , KGB chairman in 1967 – 1982 and General Secretary from 1982 to 1984 , the KGB engaged in the suppression of political dissent and maintained an extensive network of informers , reasserting itself as a political actor to some extent independent of the party-state structure , culminating in the anti-corruption campaign targeting high party officials in the late 1970s and early 1980s
Stalinist terror
Great Purge
Soviet Union