THIS year marks the 20th anniversary (周年纪念) of the fall of the Berlin Wall. The Wall was built by the then East Germany in 1961 to stop its people from going to West Germany. It was torn down in 1989 and in 1990 the two Germanys were unified (统一). The wall is seen as one of the major symbols of the Cold War (1945–1991), which was the political conflict, military tension, and economic competition between the Soviet Union and its socialist allies, and the Western world led by the US after World War II.