This chapter frames the conceptual and analytical framework of the book by bringing together the literature on norm contestationNorm contestation and EU foreign policy. To this end, this chapter provides a review of the constructivist literature on normNorm studies. The literature review serves to highlight that normsNorm have a dual quality whereby they are both stable and contested. And the exercise of contestation, depending on the normNorm community to which the actor belongs, will take the form of applicatory contestationApplicatory contestation (within the normNorm community); or alternatively, if the contestation comes from outside, it will take the form of validity contestationValidity contestationas oppositionOpposition, or as dissent. This literature is set in the context of the EU, where the Union is defined as a single normNorm community. In addition, the chapter explores the complexity of the European foreign policy system. Thus, in considering contestation of EU foreign policy, it examines whether normsNorm are contested within the intergovernmentalIntergovernmental system (i.e., Member States as the main actor) or within shared competences (i.e., Member States are not the only actor). However, it is postulated that within the EU, both applicatory and validity contestationValidity contestation are observed. The latter has profound consequences for the EU. Ultimately, the conceptual and analytical framework serves as background for the analysis of the three case studies presented in the following chapters.