Piano Solo was an envisaged plot for an Italian coup in 1964 requested by then President of the Italian Republic, Antonio Segni. It was prepared by the commander of the Carabinieri Giovanni de Lorenzo in the beginning of 1964 in close collaboration with the Italian secret service SIFAR, CIA secret warfare expert Vernon Walters, William Harvey, then chief of the CIA station in Rome, and Renzo Rocca, director of the Gladio units within the military secret service SID.
The plan was delivered on May 25: it consisted of a set of measures to occupy certain institutions (Quirinale in Rome) and essential media infrastructures (television, radio), as well as the neutralization of the Communist Party (detention of cadres of the Italian Communist Party, as well as takeover of the premises of the PCI, the PSI, the PSIUP and newspaper L' Unità) .
It is was also planned to deport the political cadres of the PCI to a secret base in Sardinia, the premises also used by the Italian Gladio network at Capo Marrargiu. The list of people to be deported also included intellectuals such as Pier Paolo Pasolini.
The secret was badly guarded, since as early as summer rumors of a coup were circulating during the difficult negotiations that lead to the formation of the government Aldo Moro (June 26-July 17).
The coup plans were investigated in 1967, when the journalist Eugenio Scalfari and Lino Jannuzzi uncovered the attempt in the Italian news magazine L'Espresso in May 1967. However, the results of the official investigation remained classified until the early 1990s. It was released by premier Giulio Andreotti to the parliamentary investigation into Operation Gladio. L'Espresso mentioned that some 20,000 Carabinieri were supposed to be deployed around the country, with 5,000 of them taking over Rome, including publishing outlets and the Communist headquarters.
The Financial Times posed the possibility that the paper coup was simply used as a way to sway coalition talks between the Christian Democrats and Socialists. President Antonio Segni was apparently running out of patience with the demands from Pietro Nenni.
- Cento Bull, Anna (2007). Italian Neofascism: The Strategy of Tension and the Politics of Nonreconciliation, Oxford: Berghahn Books, ISBN 1-84545-335-2
- Ganser, Daniele. Nato's Secret Armies: Operation Gladio and Terrorism in Western Europe. Cass, London, 2004.
- Cento Bull, Italian Neofascism, p. 4
- "Twenty-Six Years Later, Details of Planned Rightist Coup Emerge". Associated Press. 1991-01-05.
- "Comic opera themes in Solo plot". Financial Times. 1991-05-01.