This thesis seeks to understand underlying reasons why Sweden’s long tradition of non-alignment suddenly changed in the wake of Russia’s invasion of Ukraine in 2022. It argues that it was not solely due to strategic chock. The thesis is based on the theory framework of national role conception, which has the conceptual mechanism for understanding foreign policy decision-making dynamics. Methodologically, it focuses on narratives from an interpretive perspective to discover role perceptions and role changes. Empirically, this is analysed based on the defence policy, during the period 2014 to 2022, and the transformation that took place of Swedish defence. The result shows a gradual shift from previous core political values, enabling a different perception of roles.