The decision to join the North Atlantic Pact in 1949 constituted a major breakaway from traditional security policies in Denmark and Norway. Even Sweden, which in the end decided to remain nonaligned, went through a period of considerable reevalution of established trends of thought. In this study Professor Magne Skodvin describes and analyzes some major phases in the series of events that caused Norway to become a charter member of the North Atlantic Alliance and directed Denmark to follow. Professor Skodvin has drawn heavily on material from archives in the Norwegian Foreign Office, the Public Record Office in London, and the National Archives in Washington D.C.