The traditional distinction between military and law enforcement operations is increasingly difficult to uphold. This gives rise to a number of difficult and complicated challenges in regard to the handling of detainees. Legal ambiguity may lead to operational uncertainty, which may hamper the efficiency of a given United Nations (UN)-mandated international military operation. It is in the interest of no one, not least the detained individual. The author argues that the Copenhagen Process on the Handling of Detainees in UN-mandated international military operations is a necessity to ensure the full protection of any individual detained during an UN-mandated international military operation and thereby ensuring the efficiency of the efforts of the international community to bring stability and peace to States and regions in dire need. On the key legal question concerning the relationship between international humanitarian law and human rights law, it is necessary to conduct a thorough analysis of the relevant provisions of both bodies of international law in context. When this is done, most of the claimedincongruities between the two bodies of law disappear – and thereby also the basis for the sometime heateddiscussions between the advocates of one or the other body of law.