Italian prime minister Giulio Andreotti reveals to the Italian parliament the existence of Gladio, the Italian "stay-behind" clandestine paramilitary NATO army, which was implicated in false flag terrorist attacks implicating communists and anarchists as part of the strategy of tension from the late 1960s to early 1980s.

Operation Gladio is the codename for clandestine "stay-behind" operations of armed resistance that were organized by the Western Union (WU), and subsequently by NATO and the CIA, in collaboration with several European intelligence agencies. The operation was designed for a potential Warsaw Pact invasion and conquest of Europe. Although Gladio specifically refers to the Italian branch of the NATO stay-behind organizations, "Operation Gladio" is used as an informal name for all of them. Stay-behind operations were prepared in many NATO member countries, and some neutral countries.During the Cold War, some anti-communist armed groups engaged in the harassment of left-wing parties, torture, terrorist attacks, and massacres in countries such as Italy. The role of the CIA and other intelligence organisations in Gladiothe extent of its activities during the Cold War era and any responsibility for terrorist attacks perpetrated in Italy during the "Years of Lead" (late 1960searly 1980s)is the subject of debate.

In 1990, the European Parliament adopted a resolution alleging that military secret services in certain member states were involved in serious terrorism and crime, whether or not their superiors were aware. The resolution also urged investigations by the judiciaries of the countries in which those armies operated, so that their modus operandi and actual extension would be revealed. To date, only Italy, Switzerland and Belgium have had parliamentary inquiries into the matter.The three inquiries reached differing conclusions as regarded different countries. Guido Salvini, a judge who worked in the Italian Massacres Commission, concluded that some right-wing terrorist organizations of the Years of Lead (La Fenice, National Vanguard and Ordine Nuovo) were the trench troops of a secret army, remotely controlled by exponents of the Italian state apparatus and linked to the CIA. Salvini said that the CIA encouraged them to commit atrocities. The Swiss inquiry found that British intelligence secretly cooperated with their army in an operation named P-26 and provided training in combat, communications, and sabotage. It also discovered that P-26 not only would organize resistance in case of a Soviet invasion, but would also become active should the left succeed in achieving a parliamentary majority. The Belgian inquiry could find no conclusive information on their army. No links between them and terrorist attacks were found, and the inquiry noted that the Belgian secret services refused to provide the identity of agents, which could have eliminated all doubts. A 2000 Italian parliamentary report from the left wing coalition Gruppo Democratici di Sinistra l'Ulivo reported that terrorist massacres and bombings had been organised or promoted or supported by men inside Italian state institutions who were linked to American intelligence. The report also said the United States was guilty of promoting the strategy of tension.

Operation Gladio is also suspected to have been activated to counter existing left-wing parliamentary majorities in Europe.The US State Department published a communiqu in January 2006 that stated claims the United States ordered, supported, or authorized terrorism by stay-behind units, and US-sponsored "false flag" operations are rehashed former Soviet disinformation based on documents that the Soviets forged.The word gladio is the Italian form of gladius, a type of Roman shortsword.

Giulio Andreotti (US: AHN-dray-OT-ee, Italian: [ˈdʒuːljo andreˈɔtti]; 14 January 1919 – 6 May 2013) was an Italian politician and statesman who served as the 41st prime minister of Italy three times (1972–1973, 1976–1979, and 1989–1992) and leader of the Christian Democracy party; he was the sixth longest-serving prime minister since the Italian Unification and the second longest-serving post-war prime minister. Andreotti is widely considered the most powerful and prominent politician of the so-called First Republic.Beginning as a protégé of Alcide De Gasperi, Andreotti achieved cabinet rank at a young age and occupied all the major offices of state over the course of a forty-year political career, being seen as a reassuring figure by the civil service, business community, and Vatican. In foreign policy, he guided Italy's European Union integration and established closer relations with the Arab world. Admirers of Andreotti saw him as having mediated political and social contradictions, enabling the transformation of a substantially rural country into the world's fifth-biggest economy. Critics said he had done nothing to challenge a system of patronage that had led to pervasive corruption. Andreotti staunchly supported the Vatican and a capitalist structure, while opposing the Italian Communist Party. Following the popular Italian sentiment of the time, Andreotti also supported the development of a strong European community playing host to neo-liberal economics. Though Andreotti belonged to the right wing of Christian Democracy, he was not averse to the implementation of the European Social Fund and the European Regional Development Fund in building the European economy.At the height of his statesman career, Andreotti was subjected to criminal prosecutions and charged with colluding with Cosa Nostra. Courts managed to prove that he was undoubtedly linked with them until 1980; however, the case was closed due to past statutes of limitations. The most sensational allegation came from prosecutors in Perugia, who charged him with ordering the murder of a journalist. He was found guilty at a trial, which led to complaints that the justice system had "gone mad". After being acquitted of all charges, in part due to statute-barred limitations, Andreotti remarked: "Apart from the Punic Wars, for which I was too young, I have been blamed for everything that's happened in Italy."In addition to his prime ministerial posts, Andreotti served in numerous ministerial positions, among them as Minister of the Interior (1954 and 1978), Minister of Finance (1955–1958), Minister of Treasury (1958–1959), Minister of Defence (1959–1966 and 1974), Minister of Budget and Economic Planning (1974–1976), and Minister of Foreign Affairs (1983–1989), and was a Senator for life from 1991 until his death in 2013. He was also a journalist and author. Andreotti was sometimes called Divo Giulio (from Latin Divus Iulius, "Divine Julius", an epithet of Julius Caesar after his posthumous deification), or simply Il divo (from the eponymous movie).