In spite of the long tradition and strong national identity of military non-alignment, the Social Democratic government enabled a profound redefinition of the national interest into an application for a Swedish membership of NATO. Through a critical discourse analysis, this thesis will explore how this was made possible, focusing on the social construction of national interests. Based on constructivism and ideas of Jutta Weldes, three main concepts were identified guiding the discursive analytical framework: the security imaginary of a state, subject positions, and chains of connotations. Furthermore, the analysis shows that this radical shift in the Swedish security policy primarily occurred through reinforcing an image of ‘the Russian threat’, as well as through new subject positioning where NATO was moved closer to Sweden and ‘the self’, followed by particular chains of connotations. These findings emphasize the importance of applying a critical lens to explore perceptions and interpretations within discourse, the constitutive function of language and the hidden meanings behind it.