Reading through the article it appears that the group that carried out the most assassination was the Brigado Rosso, or Red Brigades. Interestingly, they also killed a prominent politician of the Christian Democrats, Aldo Moro, who was actively looking into working with the communist party, and his assassination killed his party’s plans to work with the Communist Party.

The CIA appears to have been involved only marginally, being mentioned only only at one point where fascists ask them if the USA would theoretically support a coup. (Technically they’re also mentioned in the list of parties involved in the conflict, as alleged supporters of the fascists). While this doesn’t prove that they weren’t involved, I did expect there to be more proven CIA meddling based on your earlier claims.

It appears that the CIA wasn’t to blame for the leftist’s. In fact, it seems like the Marxist-Leninist Red Brigades killed people until they had no allies left, thus being unable to sustain their campaign of assassinations. So, yeah, basically your source completely undermines your position.