Ongoing and concluded PhDs

PhD researcher or student information

Júlia Zomignani Barboza

Discipline: Law

Degrees BA: Law


International Humanitarian Law and Human Rights

PhD Research Information

Undesirable but unreturnable: striking the correct balance between the rights of aliens and national security

Brief description:

Undesirable but unreturnable persons are aliens who cannot be returned to their country of origin due to human rights concerns but are also undesirable in their country of current residence because they are considered to pose a threat to national security. In matters relating to immigration, the notion usually relates to the alien’s criminal activities or suspect involvement in terrorist acts. This thesis aims to identify an optimal national solution to the phenomenon of undesirable but unreturnable migrants that strikes the right balance between national security and internationally recognised rights of individuals who fall under this category.

Alternative solutions have been proposed to this issue, but they all pose challenges to the receiving state. For example, domestically prosecuting such aliens for crimes committed abroad on the basis of universal jurisdiction is difficult since the distance between where the acts have been committed and where the criminal proceedings take place makes it hard and expensive to obtain evidence. Sending these aliens back to their country of origin with diplomatic assurances that they will not be subjected to torture or degrading treatment might be a solution, but it cannot be treated as the default way to deal with such category of migrants[1], since assurances by themselves are not sufficient to remove the human rights concerns that make an alien unreturnable. The option to extradite or transfer them to an international tribunal also seems unlikely, as “[i]nternational tribunals and courts are only interested in prosecuting a limited number of individuals, typically those individuals considered to be the ‘most responsible’ or directly involved.”[2]

In view of the limitations of the options above, scholars have concluded that creating a balancing test seemed to be the most promising solution to the issue of undesirable but unreturnable migrants.[3] Building on that conclusion, this research will first design a balancing test to be applied to this issue based on the case law of judicial or quasi-judicial international human rights bodies and national courts. It will then proceed to evaluate four different national solutions to analyse whether they follow the proposed test. Finally, an original comparison between the different solutions will be made to determine which one strikes the best balance between internationally recognised individual rights of the migrants in question and national security.

[1] Gilbert, G. (2017). Undesirable but Unreturnable Extradition and Other Forms of Rendition, p. 57. Journal of International Criminal Justice, 15(1), 55–74
[2] Gilbert, G. (2017). Undesirable but Unreturnable Extradition and Other Forms of Rendition, p. 57. Journal of International Criminal Justice, 15(1), 55–74
[3] Refugee Law Initiative, Arts & Humanities Research Council and Center for International Criminal Justice (2016), p. 5.


Keywords: EU Migration Law, Human Rights, international refugee convention, international refugee law, Undesirable, Unreturnable, national security

Language(s) of writing: English

Country: Belgium

Home University:

Vrije Universiteit Brussel (VUB)


Law and Criminology

Supervisor: Júlia Zomignani Barboza
Start date: 01-10-2018
PhD current status: PhD Defended
PhD research funded by:
Name of grant:
Added to catalogue on: 21-05-2019

Additional information: