In the last decades the usage of ‘strategic partnership’ as a conceptual framework for cooperative relationships between international political actors has been increasing. However, there is a lack of understanding both in the academia and within the policy-making community regarding the meaning of this expression. This thesis discusses the nature and uses of concept of ‘strategic partnership’ in international politics. Based on ontological, epistemological and methodological assumptions from the Philosophy of Language, Pragmatics, Social Constructivism, the English School of International Relations and Positioning Theory, I present a pluralist theoretical framework to assess the uses of ‘strategic partnership’ in international politics not as a descriptive concept based on fixed properties but as a fluid political concept. I analyze the uses made of ‘strategic partnership’ in the context of the relations between the EU and the BRIC countries (Brazil, Russia, India and China) and draw important conclusions for understanding not only the EU’s strategic partnerships but also the uses of ‘strategic partnership’ in the language of international politics. I demonstrate that ‘strategic partnership’ is turning into a foreign policy concept with three functions. Firstly, it is a label of demarcation and hierarchization of partners. Secondly, it is a normative instrument through which the EU attempts to advance and implement its ‘structural foreign policy’, associated with values like ‘democracy’ and ‘human rights’ and the norm of ‘effective multilateralism’. Thirdly, ‘strategic partnership’ is a constitutive ‘speech act’ used to constitute and reconstitute the rules of engagement between international political actors in terms of shared goals, internal hierarchy of the relationship, and references to particular sets of values and notions of rivalry and friendship. Finally, the thesis assesses the implications of a language-based approach to ‘strategic partnership’ for agency, policy and theory.