Political, economic, and cultural tensions in the late 1960s sharply increased nationalist feeling in Croatia. In 1967 Croatian intellectuals, including Miroslav Krleza, the most respected literary figure in Croatia, signed a statement denying the validity of Serbo-Croatian as a historical language and promoting Croatian as a distinct language. The ensuing polemics escalated into a conflict over discrimination. Croatian historians recalled exploitation of Croatia by the Serb-dominated prewar government, and Croatian economists complained of disproportionate levies on Croatia for the federal budget and development fund. Party leaders in Zagreb won popularity by defending the economic interests of the republic, and nationalist leadership groups, including Matica Hrvatska, Croatia's oldest cultural society, began calling for constitutional changes to give the republic virtual independence. In November 1971, university students went on strike and demonstrators marched through the streets. Tito pressed Croatian party leaders to quiet the nationalists, but the unrest continued. Finally, police and soldiers arrested hundreds of student leaders. The authorities disbanded Matica Hrvatska and purged "nationalists" and liberals from all Croatian organizations and institutions.

The rise of nationalism halted the liberal movement in the national party. Tito called for stricter adherence to democratic centralism and proclaimed that the League of Communists would remain the binding political force of Yugoslavia, and that the league could not decentralize without endangering the country's integrity. He also called for the party to reassume its leading role and reestablish its control over the country's political and economic life. Through 1972 Tito overcame unprecedented local defiance to purge reformist party leaders in Serbia, Slovenia, Macedonia, and Vojvodina. He replaced them in most instances with antireform party veterans who had displayed less political talent than their predecessors but were considered more politically reliable. In 1974 the Party's Tenth Congress elected Tito party president for life and proclaimed that Yugoslavian "self-managed socialism" would remain under firm party control. The leadership muzzled the press, arrested dissidents, pressured universities to fire outspoken professors, and redoubled efforts to promote Tito's cult of personality.

Data as of December 1990