During the Cold War, the states in Eastern Europe were of the Soviet Union and acted as a between Western Europe and the Soviet Union.

During the Cold War, both Eastern Europe and Southeast Asia were , as both regions were trapped between the opposing forces of Communism and democracy.

include the borders between Chad and Libya; the two Koreas

include the borders between DRC and Uganda; France and Spain

include the borders between India and Pakistan; Northern Ireland (U. K) and Ireland

A no longer serves as a boundary, but may continue to serve as a reminder