Operation Gladio and the NATO stay-behind networks

On 24 October 1990 Italian Prime Minister Giulio Andreotti confirmed Gladio's existence to a parliamentary committee investigating terrorism, and submitted a written report. The European Parliament passed a resolution on 22 November 1990 condemning the networks' evasion of democratic control and calling for investigations. Belgium and Switzerland both convened parliamentary inquiries; the Swiss report on the P-26 network ran to hundreds of pages. Arms caches were subsequently recovered in several countries.

The existence of the networks is therefore settled fact. Their peacetime conduct is where the record becomes genuinely mixed. Italian judicial investigations into the 1980 Bologna station bombing and the 'strategy of tension' produced convictions of neo-fascist militants and of intelligence officials for obstruction, and Italian courts have found links between elements of the security services and far-right groups. General Gianadelio Maletti, former head of Italian counter-intelligence, testified in 2000 that the CIA had supported far-right groups to promote a strategy of tension.

What has not been established is a NATO-wide directive to commit domestic terrorism. Careful historians distinguish between a documented clandestine structure, documented Italian collusion in specific cases, and the broader claim that Gladio itself carried out bombings across Europe — for which the evidence is contested and country-specific.