August 13, 1961: "The Berlin border between East and West Berlin is closed. The zonal boundary is sealed in the morning by East German troops. “Shock workers” from East Germany and Russia seal off the border with barrier of barbed wire and light fencing that eventually became a complex series of wall, fortified fences, gun positions and watchtowers heavily guarded and patrolled. In the end, the Berlin Wall was 96 miles (155 km) long and the average height of the concrete wall was 11.8 ft (3.60 m). Over the course of the Wall’s existence, 133 people were confirmed killed trying to cross into West Berlin according to official sources, while a victims’ group puts the number at over 200 dead. There were also some 5,000 successful escapes into West Berlin. The August 13 operation lasted 24 hours." (Source: The Cold War Museum - Berlin Wall Timeline)

November 9, 1989: "The fall of the Berlin Wall signaled the end of the Cold War and was followed by the dissolution of the Warsaw Pact and the breakup of the Soviet Union. The reunification of Germany in October 1990 brought the territory of the former East Germany into the Alliance. The new democracies of Central and Eastern Europe were eager to guarantee their freedom by becoming integrated into Euro-Atlantic institutions". (Source: Evolution of NATO's "Open Door Policy", 3 December 2015)

This LibGuide is part of the NATO Declassified project, launched in December 2016. This NATO web-based platform is planned to expand. Over time, it will offer more historical content and features.

The NATO web pages:

• The Berlin Crisis and the Allied Response
• Berlin Crisis timeline
• Experts' Corner on Berlin (The Fall of the Wall Era)
• NATO Declassified: The Fall of the Wall and the Cold War era.
• NATO marks 50 years since the 1961 Berlin Crisis (16 August 2011)
• 50th anniversary of Berlin crisis marked by exhibition and release of declassified documents (30 June 2011)
• NATO leaders dedicate Berlin Wall and 9/11 memorials (25 May 2017)
• NATO commemorates 30th anniversary of the Fall of the Berlin Wall (6 November 2019)
• NATO Archives' collection of documents on Military Planning for Berlin Emergency (1961-1968)
• the NATO Military Matters issue on The beginnings of NATO’s military structure: birth of the Alliance to the fall of the Berlin Wall (2006)
• the NATO Topic pages on 
  • Strategic Concepts
  • Enlargement

A selection of key analyses and papers:

• The Berlin Wall: A Secret History, by the German History's expert Frederick Taylor (published in History Today in February 2007)
• During the Meeting of NATO Heads of State and Government held on 25 May 2017, two segments of the Berlin Wall (a gift from Germany to NATO) were unveiled in the new NATO Headquarters.
• the Central Intelligence Agency's booklet: A City Torn Apart: Building of the Berlin Wall 
• the U.S. National Archives and Records Administration's project: A City Divided: Life and Death in the Shadow of the Wall
• The U.S. National Archives and Records Administration's publications on Berlin: 
  • NATO and the Berlin Crisis of 1961: Facing the Soviets While Maintaining Unity, by Dr. Gregory W. Pedlow
  • The U. S. Military Response to the 1960 - 1962 Berlin Crisis, by Dr. Donald A. Carter, details the actual events leading up to the construction of the Berlin Wall.
  • On the Front Lines of the Cold War: The Intelligence War in Berlin [Conference at the Teufelsberg and the Alliierten Museum, Germany, on 10-12 September 1999], by Dr. Donald P. Steury
  • Bitter Measures: Intelligence and Action in the Berlin Crisis, 1961, by Dr. Donald P. Steury
  • The Wall Remained…, by Dr. Donald P. Steury
  • A Brief History of the Berlin Crisis of 1961, by Neil Carmichael
  • Crisis Over Berlin, A Study Produced by the Historical Office, United States Department of State.
• The Berlin Wall History, the Berlin Wall Timeline, and the Berlin Wall Maps, on the 'Berlin Wall Online' platform (2015)
• The Berlin Wall: A World Divided, 1961-1989 by Frederick Taylor, Harper Collins e-book (2006)
• Helmut Kohl, who died on 16 June 2017, had looked back on the night the Berlin Wall fell: "The Fall of the Wall Revisited" Project Syndicate (4 November 1999)
• In German: "Gesamtkonzept zur Erinnerung an die Berliner Mauer: Dokumentation, Information und Gedenken" by the Berlin Wall Memorial - Gedenkstätte Berliner Mauer (2006)
• "Information, Persuasion, or Consultation? The Western Powers and NATO during the Berlin Crisis, 1958-1962" by Bruno Thoss, in: "Transatlantic Relations at Stake: Aspects of NATO, 1956-1972, Center for Security Studies (2006)
• For an overview on NATO and the Warsaw Pact: "NATO in the 1960s: Challenges beyond Deterrence", a conference organized and hosted by the Center for Security Studies at ETH Zurich in 2004.

Map shown on the occasion of the 50th anniversary of Berlin crisis marked by exhibition and release of declassified documents at NATO HQ (23-29 June 2011).

During the Meeting of NATO Heads of State and Government held on 25 May 2017, two segments of the Berlin Wall (a gift from Germany to NATO) were unveiled in the new NATO Headquarters. Read the NATO Secretary General's remarks  at the dedication of the Berlin Wall Memorial here.