Public disclosure of NATO information

  • Last updated: 04 Oct. 2022 11:33

The NATO Archives works to improve the transparency of the Alliance through the Public Disclosure Programme. It aims to stimulate discussion, facilitate research on NATO and, more generally, support NATO’s ongoing engagement with the public. So far, the programme has declassified and publicly disclosed over 500,000 documents spanning across over 40 years of NATO history from 1949 to 1990.


  • The NATO Archives raises awareness of the Organization’s archival heritage through the declassification and public disclosure of records of permanent value related to the evolution of NATO, its missions, consultations and the decision-making process. 
  • NATO has publicly disclosed documents across all its primary functions.  Subjects include political affairs, defence and military issues, scientific cooperation and documents originating from NATO’s highest political decision-making body, the North Atlantic Council.
  • NATO documents with permanent value and that are 30 years or older go through a declassification and disclosure process and, once approved, become freely available to the public.
  • So far, over 62,000 of the 500,000 publicly disclosed documents are available through the NATO Archives Online portal. The others are available for consultation at the NATO Archives Reading Room.
  • Each year, thousands of new documents are proposed for public disclosure by the NATO Archivist.


NATO information disclosed so far to the public

Documents from hundreds of NATO committees, working groups, divisions and bodies have been proposed and released for public disclosure.  The majority of them are available up to 1990 and have a French and English version, the two official languages of the Alliance.  A short list of the principal series includes:

Civil Organisation Records Military Organisation Records
North Atlantic Council Military Committee
Private Office Defence Committee
AC/119 - Political Affairs Military Representatives Committee
AC/127 - Economic Affairs Standing Group
DPC - Defence Planning  


Declassification and public disclosure processes

The NATO Archives has two processes by which documents can be declassified and made publicly available, namely the systematic process and the ad-hoc process. 

Systematic declassification and public disclosure

The systematic declassification and public disclosure process is proposed on an annual basis by the NATO Archivist to Allied countries.  The documents proposed during this process are always at least 30 years old and of permanent value.  For instance, in 2021, some 5,000 military and civilian documents, up to and including 1990, were proposed for public disclosure.  The documents are collected by the NATO Archives and sent to the member countries having equity for approval (i.e., who were member countries at the time the document was published) under the silence procedure, usually one calendar year after being proposed.  Once approved, the NATO Archives digitally stamps the documents as “Publicly Disclosed” and makes these available in its Reading Room.  A member country can also choose to withhold a document and is required to give a reason for withholding.  If withheld, the document will be re-examined for public disclosure in no more than 10 years.

The ad-hoc disclosure process

The ad-hoc disclosure process allows for members, organisations or the NATO Archives to propose documents that do not fall under the above systematic request.  Ad-hoc requests usually come from researchers or journalists, who can make a “Freedom of Information” request to their national governments.  The national government then makes the request to the NATO Archivist. 

Ad-hoc requests can propose a single document or a series of documents, and can occur multiple times in the year and simultaneously with the systematic request and other ad-hoc requests.  In 2018, 1,500 documents were declassified and publicly disclosed through the ad-hoc process.  Some highlights from that year include files on the F104-G Starfighter and FIAT G.91 programmes, NATO’s evaluation on the development of the Czechoslovakia situation in spring 1968 and records related to NATO’s former War Headquarters in Malta.  A shorter silence period is usually given to ad-hoc requests since fewer documents are usually proposed for declassification under this process.

Access to NATO’s history

The NATO Archives and Public Disclosure Programme offer several ways to access and use the publicly disclosed holdings of NATO.  The full set of all documents is always available through the NATO Archives Reading Room, located in NATO Headquarters, Brussels, Belgium.  In order to visit the Reading Room, a form must be filled out and sent to the NATO Archives by email at least 30 working days before any visit.   Finding aids are available in the Reading Room and most documents are accessible as PDFs on research stations.

The NATO Archives has also made available some 62,000 documents through an online tool called NATO Archives Online.  Documents are available here as PDFs that can be freely downloaded by the public.  These documents represent the first 10 years of Alliance history through the lens of its international civilian and military staffs.  Historical press releases and NATO publications up to the year 2000 are also available through this portal.  Fonds and series are described according to the internationally accepted ISAD(G) standard, meaning that researchers have access to detailed descriptions of hundreds of series.   

Please keep in mind the requirements for use of NATO content when using any NATO documents.

History of declassification and public disclosure at NATO

Declassification and downgrading of sensitive documents has featured in the NATO Security Policy since 1955, when it was used to reduce the volume of classified material.  Declassification was done on an ad-hoc basis during the first two decades and depended on the needs or initiatives of a service or a committee.  In 1973, the Central Registry initiated a first systematic downgrading and declassification programme for older documents.  Between 1973 and 1981, NATO downgraded and declassified some 37,000 documents, representing the first 15 years of NATO history.  After 1981, systematic declassification stalled due to a revised and stricter Security Policy, which brought the programme to a standstill.

Once declassified, the documents were still considered official NATO documents and could only be released on an individual basis.  A historian 30 years ago wishing to consult the documents would need support from their national delegation and the direct approval of the NATO Secretary General.  Meetings were convened with archival experts and national archivists to discuss the situation at NATO.  An increasing demand from researchers for access to documents, a push for greater organisational transparency and the pressure from national archivists led to the creation of a real archive.  A first consultant was hired in 1989 to report on the state of the documents, and two more archival consultants were brought in in 1991-1994 and 1996-1998 to generate inventories, propose documents for public disclosure and prepare a longer-term archival programme.  The consultants recommended that an advisory body be established to assist the North Atlantic Council in the corporate management of the NATO Archives.

The NATO Archives officially opened on 19 May 1999 in conjunction with the 50th anniversary of the founding of the Alliance. The formal establishment of the NATO Archives and, with it of the Archives Committee, led to the availability of the Alliance’s records to the public for the first time. With NATO Archives Online, researchers are able to enjoy even greater access to publicly disclosed NATO documents related to the Alliance’s history, evolution and decision-making process.