It included guard towers placed along large concrete walls,[4] accompanied by a wide area (later known as the "death strip") that contained anti-vehicle trenches, beds of nails and other defenses.

[5] The Soviet Bloc propaganda portrayed the Wall as protecting its population from "fascist elements conspiring to prevent the will of the people" from building a communist state in the GDR.

In 1989, a series of revolutions in nearby Eastern Bloc countries (Poland and Hungary in particular) and the events of the "Pan-European Picnic" set in motion a peaceful development during which the Iron Curtain largely broke, rulers in the East came under public pressure to cease their repressive policies.

[17][18] As the Soviet Union already had an armed presence and political domination all over its eastern satellite states by 1955, the pact has been long considered "superfluous",[19] and because of the rushed way in which it was conceived, NATO officials labeled it a "cardboard castle".

[34] Yuri Andropov, then the CPSU Director on Relations with Communist and Workers' Parties of Socialist Countries, wrote an urgent letter on 28 August 1958 to the Central Committee about the significant 50% increase in the number of East German intelligentsia among the refugees.

[49] The brain drain of professionals had become so damaging to the political credibility and economic viability of East Germany that the re-securing of the German communist frontier was imperative.

[56] A feeling of miscalculation and failure immediately afterwards was admitted by Kennedy in a candid interview with New York Times columnist James "Scotty" Reston.

[57] On Saturday, 12 August 1961, the leaders of the GDR attended a garden party at a government guesthouse in Döllnsee, in a wooded area to the north of East Berlin.

During the construction of the Wall, National People's Army (NVA) and Combat Groups of the Working Class (KdA) soldiers stood in front of it with orders to shoot anyone who attempted to defect.

West Berliners demonstrated against the Wall, led by their Mayor (Oberbürgermeister) Willy Brandt, who criticized the United States for failing to respond and went so far as to suggest to Washington what to do next.

"[61] United States and UK sources had expected the Soviet sector to be sealed off from West Berlin but were surprised by how long the East Germans took for such a move.

On 9 August 1961, the NSA intercepted an advance warning information of the Socialist Unity Party's plan to close the intra-Berlin border between East and West Berlin completely for foot traffic.

In an October 1973 order later discovered by researchers, guards were instructed that people attempting to cross the Wall were criminals and needed to be shot: Do not hesitate to use your firearm, not even when the border is breached in the company of women and children, which is a tactic the traitors have often used.

[96]Early successful escapes involved people jumping the initial barbed wire or leaping out of apartment windows along the line, but these ended as the Wall was fortified.

[100] East Germans successfully defected by a variety of methods: digging long tunnels under the Wall, waiting for favorable winds and taking a hot air balloon, sliding along aerial wires, flying ultralights and, in one instance, simply driving a sports car at full speed through the basic, initial fortifications.

[105] An airborne escape was made by Thomas Krüger, who landed a Zlin Z 42M light aircraft of the Gesellschaft für Sport und Technik, an East German youth military training organization, at RAF Gatow.

His aircraft, registration DDR-WOH, was dismantled and returned to the East Germans by road, complete with humorous slogans painted on it by airmen of the Royal Air Force, such as "Wish you were here" and "Come back soon".

The guards often let fugitives bleed to death in the middle of this ground, as in the most notorious failed attempt, that of Peter Fechter (aged 18) at a point near Zimmerstrasse in East Berlin.

The Wall gave rise to a widespread sense of desperation and oppression in East Berlin, as expressed in the private thoughts of one resident, who confided to her diary "Our lives have lost their spirit ... we can do nothing to stop them.

On 31 December 1989, American TV actor and pop music singer David Hasselhoff was the headlining performer for the Freedom Tour Live concert, which was attended by over 500,000 people on both sides of the Wall.

The live concert footage was directed by music video director Thomas Mignone and aired on broadcast television station Zweites Deutsches Fernsehen ZDF throughout Europe.

Hasselhoff sang his number one hit song "Looking for Freedom" on a platform at the end of a twenty-meter steel crane that swung above and over the Wall adjacent to the Brandenburg Gate.

[119]In a speech at the Brandenburg Gate commemorating the 750th anniversary of Berlin[120] on 12 June 1987, U.S. President Ronald Reagan challenged Mikhail Gorbachev, then the General Secretary of the Communist Party of the Soviet Union, to tear down the Wall as a symbol of increasing freedom in the Eastern Bloc: We welcome change and openness; for we believe that freedom and security go together, that the advance of human liberty can only strengthen the cause of world peace.

Because with the non-reaction of the USSR and the GDR to the mass exodus, the media-informed Eastern Europeans could feel the increasing loss of power of their governments and more and more East Germans were now trying to flee via Hungary.

The movement neared its height on 4 November, when half a million people gathered to demand political change, at the Alexanderplatz demonstration, East Berlin's large public square and transportation hub.

[129] On 9 October 1989, the police and army units were given permission to use force against those assembled, but this did not deter the church service and march from taking place, which gathered 70,000 people.

[144] For many years after reunification, people in Germany talked about cultural differences between East and West Germans (colloquially Ossis and Wessis), sometimes described as Mauer im Kopf (The wall in the head).

They can be found, for instance, in presidential and historical museums, lobbies of hotels and corporations, at universities and government buildings, and in public spaces in different countries of the world.

Chancellor Angela Merkel joined with President Christian Wulff and Berlin Mayor Klaus Wowereit at the Bernauer Straße memorial park to remember lives and liberty.

"It is our shared responsibility to keep the memory alive and to pass it on to the coming generations as a reminder to stand up for freedom and democracy to ensure that such injustice may never happen again."