This project is aimed at the study and debate on the current and most relevant challenges to the security of the European Union (EU) and its Member States. From this perspective, topics as terrorism, organized crime, threats related to the use of global commons or the cyberspace will be addressed, in order to analyse EU legal solutions offered to these threats. Having in mind that they all challenge important values, principles and interests of the EU and its Members States, a multiple approach to these threats is needed to give an accurate vision of the problems that they pose to EU societies and the solutions foreseen. Common interests at stake include traditional fields of study, like the protection of human rights, threatened by States’ security strategies to protect their citizens. But they also include contemporary issues, like the protection of the cyberspace or the use of global commons, which are vulnerable and can be used to threaten international peace and security. From this perspective, the project seeks to address a real problem in our society: how the response against some global threats might jeopardize the most important assets of the International Community and in particular of the European Union and its Member States. The EU, as a main actor in International Relations has an important role to play in order to address this situation. The European legal/institutional and political framework to tackle these questions will be the main point to analyse and discuss with the different participants in the scheduled activities. The international legal framework will be borne in mind as it is the universal one in which European Union regulations are a normative subsystem. As well, legal, political and societal approaches of member States will be discussed –putting a special stress in the Spanish experience- and their implementation of European and international standards to deserve international legitimacy.