NATO
The North Atlantic Treaty Organization, was formed at Washington, D.C. on April 4, 1949 and originally comprised of 12 member nations consisting of Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom and the United States.
NATO was established during the Cold War to create a mutual defense pact aimed at containing possible Soviet aggression and blocking Soviet expansion into Europe.
NATO soon expanded its membership to include Greece, Turkey and West Germany during the Cold War which resulted in the Soviets forming its own defense organization known as the Warsaw Pact.
Later members of NATO were Spain, Hungary, the Czech Republic, Poland, Estonia, Latvia, Lithuania, Slovenia, Slovakia, Bulgaria, Romania, Albania and Croatia. NATO continues to play an important role in post-Cold War Europe.