Since the end of the 20th century, the nexus between security issues and migration has become more prominent in major countries of immigration, both among policy-makers and researchers. In the literature, this linkage is referred to as the ‘securitization of migration’ or ‘the migration-security nexus’. While this trend was reinforced in the aftermath of the terrorist attacks of 9/11 in the United States and the subsequent bombings in Madrid and London, scholars agree that the connection between these two fields is not new. Departing from the observation that, at present, security plays a major role in regulating migration, the main objective of this research project is to explore the migration-security nexus in Switzerland from the beginning of the 20th century until the present. In security studies, the notion of security has been defined as being characterized by three constitutive elements: the existence of a threat (1) that endangers a referent object (2) and thus creates a necessity for emergency measures (3) to guarantee security. ‘Securitization’ refers to the process of addressing an issue within a security framework, i.e. defining it as an existential threat to the political order and thereby making all other issues secondary. Thus, security is not used as a sign which refers to an already existing object, but the enunciation itself produces and modifies reality into a secu-rity issue. In this sense, the question to be asked is not whether migration actually does pose a threat to the host society, but how migration is turned into a security issue. In Switzerland, contrary to other countries, there has been no study which explicitly deals with the link between migration and security. The proposed study is to be situated in the tradition of critical security studies which argue for a reflexive concept of security and are interested in the process of its construction and transformation as well as in securitizing processes. However, the proposed research project is char-acterized by some particularities: Our understanding of the securitization process is not limited to the discourse itself, but involves political, legal and administrative practices - especially the creation of laws or the implementation of pro-cedures - and the broader socio-political context in which these discourses and practices take place. Furthermore, we will take into account a broad range of referent objects and not limit ourselves to the political order. Finally, by not tak-ing for granted the existence of the securitization of migration in Switzerland, our approach is qualitative-inductive and aims at investigating empirically the micro-aspects of this discursive and practical linkage. The main research questions are as follows: When used in the context of migration politics and law, what precise un-derstanding of security do different actors defend in different contexts? Are there processes of securitization of mi-gration in the discourse and practice of Swiss politics, administration and law? If so, how do they work and what implications do they have? What are the particularities of the Swiss case compared to other countries? How have the notions of security and securitizing processes evolved throughout the 20th, and at the transition to the 21st, century? What differences or parallels are there in different thematic areas of migration politics and law? In order to answer these questions, we will focus on legal, political and administrative discourse and practice. The main data to be used in this respect are texts (reports, records of parliamentary debates, etc.) produced by the federal parliament and administration during the legislative process. Furthermore, federal legal bases concerning migration and security, as well as case law in the implementation of legal grounds will be analysed. Finally, a number of expert interviews will be carried out with members of administrations, parliament and courts concerning securitizing processes and the notion of security in the migration context. In order to limit the potentially vast material - temporal, legal and thematic restrictions will be defined at the outset of the study. A study of migration and security in Switzerland is warranted not only due to the above mentioned gap in research, but also because it is of a general societal interest: As securitizing processes imply the symbolic, legal and practiced exclu-sion of people who are considered to be a threat to society, a deeper understanding of the meanings of security and threat, of what lies behind such framing processes, of what implications and even side-effects it may have, as well as a critical view of the evolution of this link over time seem important.