This thesis aims to analyse the transformation of Sweden’s state identity as well as its Security and Defence Policy through a theoretical framework based on Alexander Wendt’s “Social Theory of International Relations”. By identifying factors (both internal and external) that have affected Sweden’s actions and policymaking, the thesis provides an understanding of the gradual conversion from neutrality, isolation and national defence to military non-alignment, cooperation and international operations. The thesis discusses a future renationalisation in international relations and identifies difficulties with Sweden’s policy of being militarily non-aligned in peacetime aiming for neutrality in wartime. Because of Sweden’s membership in the European Union, NATO’s Partnership for Peace, and the Declaration of Solidarity, the neutrality option does not seem particularly viable if a conflict were to arise in Sweden’s vicinity.