During the Cold War, there were a number of countries that changed sides. Some of the most notable include:
* The German Democratic Republic (GDR): The GDR was a communist state that was founded in 1949 in the Soviet-occupied zone of Germany. In 1990, the GDR joined the Federal Republic of Germany (West Germany), which was a member of NATO.
* Czechoslovakia: Czechoslovakia was a communist state that was founded in 1948. In 1989, the Velvet Revolution led to the overthrow of the communist government and the establishment of a democratic state. Czechoslovakia split into two countries, the Czech Republic and Slovakia, in 1993. Both countries joined NATO in 1999.
* Poland: Poland was a communist state that was founded in 1947. In 1989, the Solidarity movement led to the overthrow of the communist government and the establishment of a democratic state. Poland joined NATO in 1999.
* Hungary: Hungary was a communist state that was founded in 1949. In 1989, the Hungarian Revolution led to the overthrow of the communist government and the establishment of a democratic state. Hungary joined NATO in 1999.