Well, NATO still exists today, as opposed to the Iron Curtain of satellite nations of the Soviet Union.
The purpose of NATO, or the North Atlantic Treaty Organization, was an organization created for the purpose of opposing the Soviet Union after WW2 and in the coming years of the Cold War. The similar organization that opposed NATO was the Iron Curtain, or Iron Wall of countries that were essentially "puppet" states set up by the Communists of the Soviet Union. The purpose of this "Iron Curtain" was to be a buffer against the reaches of Democracy and the ideals of the West. NATO opposed Communism and the ideals of the Soviet Union, hence the me versus you scenario between NATO and the Iron Curtain.