After the crisis that happened in Berlin, many Western European nations sought to create a collective security pact with the United States of America. In April 1949, the united States entered into a peacetime military alliance, the North Atlantic Treaty Organization (NATO). There were twelve nations under the Nato pact - Belgium, Canada, Denmark, France, Great Britain, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, and the United States. They all agreed that "an armed attack against any one or more of them in Europe or North America shall be considered an attack against them all." In May 1949, NATO also agreed to create the Federal Republic of Germany specifically for West Germany. The Soviet Union's response was to establish the German Democratic Republic specifically for East Germany; the Council for Mutual Economic Assistance (COMECON). In 1955, the Soviet Union established the Warsaw Pact, a military alliance for Eastern Europe that included Albania, Bulgaria, Czechoslovakia, East Germany, Hungary, Poland, Romania, and the Soviet Union. The two powers had institutionalized the Cold War through a massive division of the continent.