Which replaced the XXX?
KGB
The KGB, an initialism for Komitet gosudarstvennoy bezopasnosti (Russian: Комите́т госуда́рственной безопа́сности (КГБ); IPA: (kəmʲɪˈtʲɛt ɡəsʊˈdarstʲvʲɪnnəj bʲɪzɐˈpasnəsʲtʲɪ), translated in English as Committee for State Security), was the main security agency for the Soviet Union from 1954 until its break-up in 1991.