Relationships between the PCI and the Soviet Union gradually fell apart as the party moved away from Soviet obedience and Marxist – Leninist orthodoxy in the 1970s and 1980s and toward Eurocommunism and the Socialist International . The PCI sought a collaboration with Socialist and Christian Democracy parties ( the Historic Compromise ) . However , Christian Democrat party leader Aldo Moro 's kidnapping and murder by the Red Brigades in May 1978 put an end to any hopes of such a compromise . The compromise was largely abandoned as a PCI policy in 1981 . The Proletarian Unity Party merged into the PCI in 1984
kidnapping and murder
Kidnapping of Aldo Moro
Italian Communist Party