Norway retained its neutrality policy until 1947, focusing on its membership in the United Nations, where Trygve Lie had become the first secretary-general. However, there was no enthusiasm for the UN at the time. Anti-communism grew with a Soviet proposal for joint control over Svalbard and especially after the 1948 Czechoslovak coup d'état, after which the Communist Party lost all influence. Norway started negotiations for the creation of a Scandinavian defense union, but instead opted to become a founding member of the North Atlantic Treaty Organization (NATO). However, Norway never allowed permanently stationed foreign troops or nuclear weapons on Norwegian soil to avoid agitating the Soviet Union, with which Norway from 1944 shared a land border. NATO financed large parts of the Norwegian military investments, which ultimately resulted in numerous airports being built during the 1950s and 1960s.