Part 1: The paper discusses the transformation of liberalism after September 11 and the development of practices of liberalism inside European societies. It proposes an alternative view to the vision of unilateralism or of Empire that most analysts are exploring. It aims to show the role of the different transnational networks of security professionals, their impact on politicians and the consequences of the shift of technologies of surveillance regarding civil liberties by proposing to combine Agamben and Foucault works with the notion of Ban Opticon. Part 2: The paper will analyze the changing relationship between new security challenges and the way new technologies transform the practice of war. The history and emerging relationship between practices of security and the principles of the democratic public sphere will also be explored. An analysis will be developed of the means and methods of threat assessment and the vulnerability of critical infrastructures, most notably the specific cases of telecommunication networks, water systems, nuclear plants, cyberspace and knowledge-based experts networks, the commercial privatisation of technologies of surveillance and control. To explore the security policies and warfare strategies that result from the security environment of a globalised world, which make Western, societies ‘risk societies’. Part 3: The tragic terrorist attacks of September 11 seem to have made all political actors aware that each home security policy is ensured at the global level, or that it was not ensured at all. The natural democratic solidarity against terrorism becomes a rhetoric common place. Not a question. Why and how the question of democracy have been bent to new times rather than questioned? Our main objective in this paper is to underline how the question of terrorism going beyond the national borders which requires mutual assistance and mutual co-operation is a symbolic, political and identity issue. The core of our intention will be thus to show how the antiterrorist fight in Europe is initially dominated by the problems of the recognition of each other Member State as an inter pares member of this whole Europe of democracies. Under this angle, the co-operation understood as a hyperbolic discourse of always more, never enough, structured on the official history of an initial deficit of the European security is then the point of conversion of the national characteristics into a common identity. In other words, the progressive installation of ad hoc European institutions envisaged according to the principle of coordination of the police and legal efforts produced a network of exchanges which ensures the circulation of significance and strong collective identity representations. Even if the fight against terrorism and by extension against organized crime is carried out by a large number of police, intelligence and judicial actors, they all are involved in the same global (re)definition of the European identity. In fact, it is because there is a complex web of different national cultures, practices in order to fight against terrorism, that according each other around a single discourse is a real political opportunity. But does this political identity construction is really stable? The different national positions after the 9.11 events seem to have turned the historical European collective identity process upside down and the democratic solidarity is everything but an embattled narrative between an us and them distinction process. In other words, by dismounting these official processes of historicization which make of the European co-operation a reality born of the dialogue around a necessary solidarity of the European States vis-à -vis to the terrorist threat, and to deal with the different discourses after the 9.11 attacks, it is rather a question of showing how the co-operation is a requirement for a political and diplomatic legibility between countries and actors of Europe. A Europe which offers the insurance of a collective common and reassuring identity: the democracy for everyone. Regarding the democratic European and national discourses after 9.11, we will answer to the question of the (re)definition of the democratic European identity. [ABSTRACT FROM AUTHOR]