In April 1968, Katushev was promoted again, when he was brought to Moscow as a Secretary of the Central Committee of the Communist Party of the Soviet Union, with responsibility for relations with the ruling parties of other communist states - ie relations with socialist countries, member countries of the Council for Mutual Economic Assistance, member countries of the Warsaw Pact) - replacing the future party leader Yuri Andropov, who had been appointed head of the KGB.

[4] His appointment coincided with the so-called Prague Spring in Czechoslovakia, an outburst of personal freedom unprecedented in a communist-ruled state, which was crushed by Warsaw Pact invasion in August.

[5] During the so-called 'normalisation' that followed, Kulakov travelled to Prague to oversee the removal of Josef Smrkovský from the post of chairman of the federal assembly, and again in April 1969 to bring about Dubcek's enforced resignation and his replacement by Gustáv Husák, who ruled Czechoslovakia until the communist system collapsed in 1991.

In May 1977, he was suddenly removed from the party secretariat, and moved to the lesser post of Deputy Chairman of the Council of Ministers of the Soviet Union, responsible for relations with other Comecon governments.

Reputedly, the reason for his demotion was that during a visit to Vietnam, he had failed in his mission to get the heads of the Vietnamese communist party to award Brezhnev a medal to mark his 70th birthday.

In the post–Soviet period of Russian history, he held executive positions in a number of commercial banks ("Diamant", "VIP–Bank").