The status of foreign fighters under international humanitarian law

Abstract

Although the phenomenon of ‘foreign fighters’ is not a new one, a reported recent increase in their numbers and in the range of countries from which they originate, the groups they join, their motivations and subsequent paths have highlighted the complicated nature of this issue and raised concerns across the world. Yet the legal obligations as well as the exact level of legal protection these individuals enjoy once they join an ongoing conflict is not entirely clear. In particular, International Humanitarian Law (IHL), which aims to protect the basic rights of individuals and groups affected by armed conflicts, does not provide specific guidance on what status they might be entitled to and, consequently, on how they should be treated. The present chapter seeks to shed some light on this matter by reviewing the main IHL treaties, their commentaries, judicial decisions rendered by international tribunals and relevant scientific contributions. It will do so by looking at IHL applicable in International Armed Conflicts (IACs) and in Non-International Armed Conflicts (NIACs), as the status these two branches of IHL confer to captured fighters is rather different. Lastly, ‘foreign fighters’ will be distinguished from ‘mercenaries’, on the basis of the legal definition currently in force under the law of armed conflict.