The concept of the Iron Curtain symbolized the ideological fighting and physical boundary dividing Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 into two separate areas from the end of World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 in 1945 until the end of the Cold War

Cold War

The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 in 1989. On either side of the Iron Curtain, states developed their own international economic and military alliances:

• The Council for Mutual Economic Assistance
  Comecon
  The Council for Mutual Economic Assistance , 1949–1991, was an economic organisation under hegemony of Soviet Union comprising the countries of the Eastern Bloc along with a number of communist states elsewhere in the world...
  
   and the military Warsaw Pact
  Warsaw Pact
  The Warsaw Treaty Organization of Friendship, Cooperation, and Mutual Assistance , or more commonly referred to as the Warsaw Pact, was a mutual defense treaty subscribed to by eight communist states in Eastern Europe...
  
   on the east side, with the Soviet Union
  Soviet Union
  The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
  
   as the most important member of each
• The European Community and the North Atlantic Treaty Organization on the west and south.

Physically, the Iron Curtain took the shape of border defences between the countries of Western

Western Europe

Western Europe is a loose term for the collection of countries in the western most region of the European continents, though this definition is context-dependent and carries cultural and political connotations. One definition describes Western Europe as a geographic entity—the region lying in the...

 and Eastern

Eastern Europe

Eastern Europe is the eastern part of Europe. The term has widely disparate geopolitical, geographical, cultural and socioeconomic readings, which makes it highly context-dependent and even volatile, and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...

 Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, most notably the Berlin Wall

Berlin Wall

The Berlin Wall was a barrier constructed by the German Democratic Republic starting on 13 August 1961, that completely cut off West Berlin from surrounding East Germany and from East Berlin...

, which served as a longtime symbol of the Curtain as a whole.

The events that demolished the Iron Curtain started in Poland

People's Republic of Poland

The People's Republic of Poland was the official name of Poland from 1952 to 1990. Although the Soviet Union took control of the country immediately after the liberation from Nazi Germany in 1944, the name of the state was not changed until eight years later...

, and continued in Hungary

People's Republic of Hungary

The People's Republic of Hungary or Hungarian People's Republic was the official state name of Hungary from 1949 to 1989 during its Communist period under the guidance of the Soviet Union. The state remained in existence until 1989 when opposition forces consolidated in forcing the regime to...

, East Germany, Bulgaria, Czechoslovakia and Romania

Communist Romania

Communist Romania was the period in Romanian history when that country was a Soviet-aligned communist state in the Eastern Bloc, with the dominant role of Romanian Communist Party enshrined in its successive constitutions...

.