Following the end of World War II, Zimyanin quickly climbed the ranks of the Communist Party of Byelorussia, becoming Second Secretary of the BCP in February 1949.
This was part of a drive initiated in Moscow by the chief of police, Lavrentiy Beria, to promote native cadres in the non-Russian SSRs.
[2] For the next 11 years, while Nikita Khrushchev controlled the communist party of the Soviet Union, Zimyanin's career suffered from the suspicion that he had been too close to Beria.
Meaning to speak to Viktoria Brezhneva, Zimyanin inadvertently rang Nina Khrushcheva and gloated about how he had attacked Khrushchev at the plenum of the Central Committee from which he had just returned, and how wonderful it was to have "dear Leonid Ilyich" as the new leader.
Speaking at a private meeting of Soviet journalists in September 1967, Zimyanin described the exiled Ukrainian writer Valery Tarsis as a madman, and Aleksandr Solzhenitsyn as "abnormal, a schizophrenic" with "a grudge against the regime",[5] and attacked the poets Yevgeny Yevtushenko and Andrei Voznesensky.