The present work looks across European Union s inside/outside by asking what power is there in a normative power narrative? And what does this narrative do to the EU? These questions are investigated by moving the focus of analysis to see to what extent and in which ways relationships set up with Others beyond Europe affect the EU political identity. Considering that NPE is the link between the EU s ontological security and its foreign policy, it cannot be thought independently of the Other. At first, the thesis offers a theorization of mechanisms of diffusion and subsequently operationalization in a dialogic perspective that endogeneize the Other from the onset. Norm reception is thus integral part of the diffusion analysis. At second, it recreates different processes of diffusion starting from NPE as foreign policy to observe the driving argument that, when the Others are endogeneized, two dilemmas of NPE arise, one political and another, more profound one, ontological. A first dilemma is political: If NPE faces resistance, it either overrules it thereby undermining its status of a different type of foreign policy; or it does not, and then does not succeed in its aim of norm diffusion. But a more profound dilemma is connected to the fact that NPE is not just a foreign policy: it is also a central component of the EU s identity project. Even if norms are diffused and policies converge, NPE may not be recognized as the superior identity to which the international order should strive. This said, if the EU becomes aware of its non-recognition, it is put before either seeing this as an aberration that will be remedied over time, or as a potential threat to its ontological security. It is hence stuck and cannot change its approach. As a result, NPE as a foreign policy can, even if successful, undermine its identity project; and NPE as identity politics can undermine its foreign policy exactly when its tendency to see itself confirmed when meeting the Other undermines its external recognition. Empirically, the ontological dilemma is observed in a case of development cooperation, the Programme between the EU and the Community of Latin American and Caribbean Countries (CELAC) on Drugs Policies (COPOLAD), which began in 2011 and was renewed in 2016. And the political dilemma is observed in a case of resistance, the quest of global access to medicines that provoked intense polarization and divergences between the EU and Brazil at the multilateral level in 2008-2009, with further developments until 2016. The thesis builds a theory and develops hypotheses connected to the NPE dilemma, seriously integrating the Other in a dialogic approach to the two paradigmatic cases. The approach explores the role of difference, contestation and power asymmetries in processual paths that end up in either of the two dilemma. Most studies that address the exercising of NPE as foreign policy tackle cases of Europeanization among EU Member States, candidates and neighboring countries. This scenario may lead to a consequent problem for both the stabilization of the EU political identity and success of foreign policy, since countries far from its borders are likely to challenge EU s discourse of exceptionalism and distinctiveness. European Studies and the EU itself did not shed light on this problem until mid-2000s. By contrast, this thesis contributes to the research agenda of norms diffusion and EU external governance on two main fronts: 1) offering a theoretical framework to analyze NPE as foreign policy, I propose that our understanding is currently insufficient to grasp dilemmas that have to do with how NPE should work; 2) it operationalizes a dialogic approach to the case studies that reveal the politics of norm reception, considering the Others as part of a fruitful communication with the EU, and not as passive receivers of NPE. Politically, it is relevant for the EU to make the NPE as a strategy coincide with its discourse on norms and principles, reducing the creation of stereotypes like double standards. In addition, to embody the Others in dialogues about the EU gives rise to the possibility of alleviating adversities encountered in the exercise of its foreign policy, as well as to strength its interregional instruments of governance.