World War I and especially World War II diminished the eminence of Western Europe in world affairs . After World War II the map of Europe was redrawn at the Yalta Conference and divided into two blocs , the Western countries and the communist Eastern bloc , separated by what was later called by Winston Churchill an " Iron Curtain " . The United States and Western Europe established the NATO alliance and later the Soviet Union and Central Europe established the Warsaw Pact
Yalta Conference
Yalta Conference
Europe