In his seminal work Strangers in Our Midst (2016a.), David Miller develops his version of liberal nationalism, where he argues for liberal states being justified in requiring immigrants to integrate themselves culturally before giving them access to formal citizenship equal to native citizens. Elsewhere, Miller (2016b.) has also expressed that there are instances when states are justified in revoking citizenships for national security reasons. This paper argues that these positions held by Miller are inconsistent with each other. To make the case against Miller for why this is, three arguments are presented. Firstly, the strict immigration policy suggested in liberal nationalism is permissible because once it is successfully completed, the naturalised citizen gains equal standing in citizenship to native born citizens. If denationalisation is applied in conjunction, but only to some, then their citizenship statis is not equal, and thus the justification for liberal nationalist immigration policy is undermined. Secondly, while it might otherwise be plausible that this injustice is permissible by viewing dual citizens secondary citizenship as a protective privilege, the necessary integration in liberal nationalism makes this response less believable. Finally, one of the most important objectives in liberal nationalism is to promote trust between members. If dual citizens are the only ones who can have their citizenship revoked, and the only reason for this is on suspicion of terrorism, then this risk promoting mistrust against these individuals, making the combination of liberal nationalism and denationalisation self-defeating.

Deprivation of citizenship is currently used in democratic states to combat international terrorism and constitutes ‘the securitisation of citizenship’. The usage of which is often justified by states as assuring national security. Among scholars, there seem to be a conflict between a perspective of rights and security, where critics usually come from the former. Can citizenship deprivation be justified from a security perspective as a counter-terrorism tool? That question is asked in this thesis. By conducting an interpretative analysis of Hobbes, the question is assessed from a security perspective and the answer is not clear cut. The research shows that even when practices are investigated through a lens of security, they are problematic as they currently stand.

The revival of citizenship deprivation raises numerous normative, legal and practical concerns. Although citizenship deprivation is not new, it has become crucial to further discuss this with regards to recent law amendments and practices on citizenship deprivation by many democratic states. Sweden is still one of few countries where citizenship is an absolute right protected by constitutional law. Nonetheless, politicians in Sweden have, over the last years, discussed the possibilities to enact the constitution to legalise denationalisation based on national security grounds. Several motions have been submitted to investigate these possibilities, but no amendments have yet been proposed.  The thesis aims, therefore, to examine whether there are legal obstacles that limit the possibilities to introduce a new provision on citizenship deprivation in Sweden. The main research question is: Are there legal obstacles to tackle terrorism through denationalisation in Sweden? To answer this question, the legal dogmatic methodology is used. The study analyses legislative sources, case law and doctrinal literature. It also reviews national regulations on citizenship deprivation in five European countries that have reformed their Citizenship Acts.  The study concludes that there are several legal obstacles in both international and EU law that limit the possibilities to denationalise citizens. However, it is not entirely illegal to deprive individuals of their citizenship. To introduce the possibility of citizenship deprivation in Sweden, the provision should fulfil the following criteria: a) denationalisation should not render a person stateless, b) the provision should not be discriminatory and apply to all citizens with dual citizenship, regardless of how they became citizen, c) prior to making the decision on denationalisation, a proportionality assessment between the individual's interest and the state's interest should be applied, d) denationalisation should have a legitimate purpose and it should be the least burdensome procedure to achieve this purpose, e) Swedish law should identify the crimes that can lead to denaturalisation, f) the decision on denaturalisation should be made at the same trial as the person in question is convicted, g) the individual should have the possibility to appeal the decision and his right to a fair trial is granted.  To conclude, the thesis emphasises that the collective development in national laws and practices on citizenship deprivation will potentially lead to a new interpretation of both EU and international law on human rights.