[4] After the liberation of Belgrade in October 1944, he remained active in communist leadership positions, including work in the Serbian republican Agitation and Propaganda commission and then as a people's representative from his home region.

[7] He arrived there for the meeting of the editors of literary magazines in socialist countries on the day when the revolution started and remained there until October 31 when he was transported back to Belgrade on a plane that brought in Yugoslav Red Cross help.

Nevertheless, he even held political speeches in favor of a revolution in Budapest and upon his return he wrote a detailed report on the matter which, by some opinions, greatly affected and shaped firm official Yugoslav view on the whole situation.

Between 1961 and 1962, Ćosić got involved in a lengthy polemic with the Slovenian intellectual Dušan Pirjevec regarding the relationship between autonomy, nationalism and centralism in Yugoslavia.

[11] Pirjevec voiced the opinions of the Communist Party of Slovenia which supported a more decentralized development of Yugoslavia with respect for local autonomies, while Ćosić argued for a stronger role of the Federal authorities, warning against the rise of peripheral nationalisms.

The polemic, which was the first public and open confrontation of different visions within the Yugoslav Communist Party after World War II, ended with Tito's support of Ćosić's arguments.

[11] Precipitated by a slow economy, opposing sides came to use Ćosić and Pirjevec as proxies in their battles for a competing vision of Yugoslavia in the early to mid-1960s.

[6] As the government gradually decentralized administration of Yugoslavia after 1963, Ćosić grew convinced that the Serbian population of the state was imperiled.

In May 1968, he gave a celebrated speech to the Fourteenth Plenum of the Central Committee of the Serbian League of Communists, in which he condemned the then-current nationalities policy in Yugoslavia.

In the 1980s, following the death of Tito, Ćosić helped organize and lead a movement whose original goal was to gain equality for Serbia in the Yugoslav federation, but which rapidly became intense and aggressive.

On Eastern Orthodox Christmas Eve of January 1993, Ćosić appeared on Serbian television to warn of demands for “national capitulation” from the West: "If we don't accept, we are going to be put in a concentration camp and face an attack by the most powerful armies of the world".

He responded:My feeling has been for a long time that the only realistic solution is one that in fact was offered by the President of Serbia [i.e. Dobrica Ćosić, then President of Yugoslavia] I think back round 1993, namely some kind of partition, with the Serbian, by now very few Serbs left but the, what were the Serbian areas being part of Serbia and the rest be what they called "independent" which means it'll join Albania.