Operation Gladio
NATO clandestine stay-behind armies in Europe during the Cold War
Operation Gladio was a clandestine NATO program that established secret "stay-behind" armies across Western Europe during the Cold War. Originally designed as resistance networks that would activate in the event of a Soviet invasion, elements of the Gladio network were implicated in terrorist attacks, political manipulation, and destabilization campaigns directed not against the Soviet Union but against left-wing political movements within NATO member states.
The program's existence was officially confirmed on October 24, 1990, when Italian Prime Minister Giulio Andreotti acknowledged Gladio before the Italian Senate. His admission triggered investigations across Europe, with similar networks confirmed in Belgium, France, Germany, Greece, the Netherlands, Norway, Portugal, Spain, Switzerland, Turkey, and the United Kingdom.
In Italy, Gladio operatives were linked to the "strategy of tension" — a series of bombings and attacks from the late 1960s through the 1980s designed to be blamed on left-wing groups and create a political climate favorable to authoritarian measures. The 1969 Piazza Fontana bombing in Milan, the 1980 Bologna railway station massacre (85 dead), and numerous other attacks were connected to far-right networks with ties to Italian military intelligence and the CIA.
Italian judge Felice Casson uncovered the connection between Gladio and domestic terrorism during his investigation of the 1972 Peteano bombing. His findings led to Andreotti's parliamentary disclosure. Subsequent European Parliament resolutions in 1990 condemned the existence of secret armies and called for full investigations, though many countries provided limited cooperation.
The full scope of Gladio remains partially classified. The CIA has never released its complete files on the program. What has been confirmed through judicial proceedings, parliamentary investigations, and declassified documents in multiple countries represents one of the most significant confirmed conspiracies of the 20th century — a secret military network that conducted terrorism against the citizens it was nominally protecting.