Challenging conventional wisdom that powerful states do as they will and small states do as they must, this article advances an analysis of small states and the role they can play as agents of change in the area of peace and security. Insights from constructivist research on foreign policy contribute to explain why some small states adopt norm entrepreneurship as a diplomatic strategy and how such strategy helps small states punch above their weight in international relations. The article is based on an in-depth case study of Sweden as a norm entrepreneur promoting the norm pertaining to the prevention of violent conflicts in the EU and UN, and it assesses the impact of the following strategies used by such a norm entrepreneur: norm construction, agendashaping, coalition-building, and support of institutionalisation.