Armed Intervention and Overlapping Conflict

Abstract

If one state uses armed force on the territory of another state, without its consent, does an armed conflict arise between the two states? If the intervening state targets an organized armed group, operating in the territorial state but beyond its control, is there instead only an armed conflict not of an international character between the intervening state and the armed group? In its 2016 Commentary on the First Geneva Convention, the ICRC answers the first question in the affirmative and the second question in the negative. In such cases of armed intervention, an armed conflict arises between the two states. Importantly, an overlapping armed conflict, not of an international character, may also exist between the intervening state and the armed group. If so, then both the law of international armed conflict and the law of non-international armed conflict apply simultaneously. Let us call this the dual classification approach. Last Fall, I offered a variety of arguments in favor of the ICRC’s position — and responded to the objections of two critics — in a series of posts on Just Security. In this paper, I revisit and partially reframe the debate over armed intervention. I then attempt to move the discussion forward by explaining *how* the law of armed conflict applies during armed intervention and other types of overlapping conflict. Most importantly, which rules regulate attacks by the intervening force against the armed group?