By unpacking a set of relevant case-studies, this panel seeks to analyse the external action of the EU with regards to both internal security and the fight against serious transnational crime. In considering the legal and institutional characteristics of the EU's relations in said fields with several third-countries or regions; the session will seek to highlight the main challenges raised by the every ever growing number of international cooperation efforts in criminal matters. A key concern in said respect will be the impact of such cooperation efforts on existing human rights protections. This has proven to be a particularly burning question considering how strongly EU values can come to be challenged when promoting external cooperation in criminal matters. In this respect, the panel will critically analyse the EU's specific role in the externalization/exportation of its professed human rights standards and norms. A transversal concern of each contribution will be to question what role the notion of 'mutual trust' might come to play in an increasingly global context where the EU has sought to impose ever more stringent requirements as pre-conditions to cooperation with third-parties. In other words, the shared puzzle of the session is to explore whether the EU is an international norm-taker or a norm-maker when dealing with issues pertaining to internal security.