NATO was formed on 4 April 1949 to provide a collective defence against outside aggression. The collapse of the Warsaw Pact and changing world situation is however causing NATO to re-assess this role.
Belgium, Canada, Czech Republic, Denmark, France, Germany, Greece, Hungary, Iceland, Italy, Luxembourg, Netherlands, Norway, Poland, Portugal, Turkey, Spain, United Kingdom, United States of America.
The North Atlantic Council is the highest authority of the Alliance. It meets at least twice a year at ministerial level.
The Defence Planning Council deals with defence matters and has the same functions and authority as the North Atlantic Council. It convenes regularly at defence minister level.