The protection of detainees in non-international armed conflict under international humanitarian law and Islamic law

Abstract Too often, conflict-related detainees are ill-treated or killed, go missing, or are held in inhumane conditions of detention. Detention occurs in all armed conflicts, including those that involve Muslim-majority States and Islamic non-State armed groups. In 2024, a substantial percentage of the International Committee of the Red Cross’s visits to detention/internment places were in Muslim-majority contexts. While the humane treatment of detainees is the responsibility of the detaining authorities, third actors, including humanitarian organizations, can and should work with those authorities with a view to making sure that they respect their obligations. To facilitate such dialogue, this article analyzes the protection of detainees under international humanitarian law (IHL) and Islamic law. As the vast majority of today’s armed conflicts are non-international in nature, the article focuses on IHL rules applicable in non-international armed conflicts (NIACs), discussing key rules of IHL and Islamic law on the protection of detainees. The selection of rules presented in this article reflects IHL rules applicable in NIACs, based on Article 3 common to the four Geneva Conventions, Additional Protocol II to the Geneva Conventions, and customary IHL rules. The article provides an issue-by-issue analysis that allows the reader to easily understand how IHL and Islamic law address specific issues on the protection of detainees in NIACs.