--- category: International Organization created: 2026-05-14 location: Brussels, Belgium summary: NATO (the North Atlantic Treaty Organization) is the Western military alliance whose Cold War infrastructure included the Gladio stay-behind networks documented in this vault; its Brussels headquarters is adjacent to the Belgian elite networks investigated in the Dutroux affair, and its expansion and intelligence coordination mechanisms are referenced throughout vault subjects. tags: - Organization - NATO - Gladio - ColdWar - Intelligence - Military updated: 2026-05-17 --- The North Atlantic Treaty Organization (NATO) is a military alliance founded on April 4, 1949, when twelve founding members - the [United States](/places/united-states/), Canada, the United Kingdom, France, [Belgium](/places/belgium/), the Netherlands, Luxembourg, Denmark, Norway, Iceland, Portugal, and Italy - signed the North Atlantic Treaty in Washington. The treaty's Article 5 commits members to mutual defense, treating an attack on any one member as an attack on all. NATO's current headquarters is located in Brussels, [Belgium](/places/belgium/), having moved there in 1967 when France under [Charles de Gaulle](/people/charles-de-gaulle/) withdrew from the integrated military command and expelled NATO from French soil.[^1] ### Gladio and Stay-Behind Networks The most consequential covert dimension of NATO documented in this vault is [Operation Gladio](/programs/operation-gladio/) - the NATO-wide network of stay-behind organizations established in the late 1940s to provide armed resistance in the event of a Soviet invasion or communist political takeover. The networks were organized under the authority of what NATO termed the "Clandestine Planning Committee" and the "Allied Co-ordination Committee," and were implemented by national intelligence services with CIA and [MI6](/organizations/mi6/) technical support. The Gladio networks are documented to have existed in at minimum 14 NATO member states, including [Italy](/places/italy/), [Belgium](/places/belgium/), [Germany](/places/germany/), France, Greece, Portugal, Turkey, the Netherlands, Luxembourg, Denmark, Norway, and Austria. Italian Prime Minister [Giulio Andreotti](/people/giulio-andreotti/) confirmed Gladio's existence in October 1990 following a parliamentary investigation prompted by Italian judge [Felice Casson](/people/felice-casson/)'s discovery of the network's records in a military intelligence archive in Rome. The Belgian network, known as SDRA8, has been linked by investigators to the unsolved Brabant massacres of 1983-1985.[^2] ### NATO Intelligence Sharing NATO's integrated military command structure required unprecedented peacetime intelligence sharing among its members, creating institutional frameworks for signals intelligence (through the [UKUSA Agreement](/programs/ukusa-agreement/) and SIGINT sharing protocols), human intelligence liaison, and counterintelligence coordination. The CIA operated as the dominant partner in these arrangements, with American intelligence budgets and collection capabilities dwarfing those of most allies. NATO's nuclear planning arrangements also required sharing of classified nuclear targeting and weapon deployment data with allied governments.[^1] ### Cold War Role NATO's primary Cold War function was deterring a Soviet conventional military attack on Western Europe through the threat of American nuclear retaliation. The alliance maintained large conventional forces in [Germany](/places/germany/) - particularly the U.S. Army's VII Corps and V Corps - alongside nuclear weapons pre-positioned at various European bases. The INF Treaty of 1987 between [Ronald Reagan](/people/ronald-reagan/) and Mikhail Gorbachev, which eliminated intermediate-range nuclear missiles, was a significant Cold War NATO diplomatic moment. After the [Cold War](/concepts/cold-war/), NATO expanded eastward to include former Warsaw Pact members, despite Russian objections. The alliance's Article 5 was invoked for the first time after the September 11, 2001 attacks, leading to NATO's deployment in [Afghanistan](/places/afghanistan/).[^1] [^1]: "North Atlantic Treaty Organization," *Encyclopaedia Britannica.* https://www.britannica.com/topic/North-Atlantic-Treaty-Organization [^2]: Ganser, Daniele. *NATO's Secret Armies: Operation GLADIO and Terrorism in Western Europe.* Frank Cass, 2005.