After WWII a "Cold War" struggle between the United States and the Soviet Union began. There were no direct military engagements between the two nations, however, each country fought to spread its political ideologies and beliefs around the world through economic and diplomatic means.

It was during this time that the Soviet Union created a buffer of communist states between itself and the rest of Europe. These "satellite" countries later became known as the Eastern or Soviet Bloc, Communist Bloc, and the Iron Curtain. The Communist Bloc was comprised of the following Central and Eastern European countries: Bulgaria, Romania, Hungary, East Germany, Poland, Albania, the Soviet Union, and Czechoslovakia.

Nations within the Communist Bloc were often held within the Soviet sphere of influence through military force. Hungary was invaded by the Red Army in 1956 after it had overthrown its pro-Soviet government; Czechoslovakia was also invaded in 1968 after a period of liberalization known as the Prague Spring. The Communist bloc came to an end with the collapse of the pro-Soviet regimes in Eastern Europe in 1989.