The aim of the present report is to provide Danish decision-makers with a comprehensive overview of the international legal framework governing security detentions in military operations that Denmark may participate in. Security detention – also known as internment – refers to deprivation of liberty without criminal charge and is a common feature in military operations, e.g. internment of prisoners of war or civilians that constitute a security threat. From 2007 to 2012, Denmark spearheaded an important international effort to develop principles with respect to handling detainees in international military operations, which came to be known as the Copenhagen Process and involved 24 states. The Copenhagen Principles, adopted at the end of that process, form a useful instrument. Yet, to secure consensus among such a sizeable number of states, they had to remain rather vague. In particular, the Copenhagen Principles did not sufficiently specify the legal basis and grounds for detention nor the procedure for detention review, including the nature, mandate and composition of the review body and the procedural safeguards to be applied. As this report concludes, those challenges arise not only in relation to non-international armed conflicts and peace operations, but also in international armed conflicts, which are outside the scope of the Copenhagen Principles. A further complicating factor is the increasing involvement of human rights bodies, such as the European Court of Human Rights (ECtHR) and the UN Human Rights Committee (HRC), with regard to security detentions in military operations. It is thus no longer in the hands of the states alone to adopt policies in line with their own interpretation of the law.

Against this background, the present report concludes with the following recommendations:

1. Denmark should build on its good experience with the Copenhagen Process and seek to align itself with like-minded states and other potential partners to develop joint security detention policies and procedures. With a smaller group of states, it will be significantly easier to find common ground and agree on specific issues left out during the Copenhagen Process. Moreover, vis-à-vis the ECtHR and the HRC, such a joint and proactive effort will have significantly more weight than reacting to subsequent human rights complaints individually and in a piecemeal fashion.

2. Denmark should, in particular, ensure that such a joint procedure for security detentions is duly enacted at the national level and that it outlines the grounds for security detention in a sufficiently detailed manner. It should cover both international and non-international conflicts as well as peacetime situations. A joint procedure that is to a large extent publicly accessible meets the requirements of foreseeability and is therefore more likely to be acknowledged in the mandates of the military operations or by the ECtHR and the HRC.

3. Denmark should also ensure that such a joint procedure for security detentions provides for the creation of pre-planned review mechanisms through an independent and impartial administrative board and with a fair procedure, including important procedural safeguards. In view of resource constraints and interoperability concerns, such mechanisms should ideally be run jointly with other states and handle all possible categories of detainees.