Public international law scholarship has identified several principles about the legal regime applicable to de facto regimes, i.e. entities that exercise effective control over territory of an existing state, but which are not recognised as an independent state or government of an existing state, and which are not being controlled by that state. The definition does not depend on warfare, nor on the recognition of an international legal personality of the de facto regime, nor on the extent of its political independence; it has been translated into positive law in Article 1(1) of Additional Protocol II (AP II) to the Geneva Conventions, providing for the material field of application of the Protocol, which applies to all armed conflicts taking place between the state party's armed forces and non-state armed groups exercising effective control over an area. Th us, our working definition covers a wide range of non-state actors from separatist administrations with a high standard of effectiveness through rebel groups de facto occupying a part of the territory of a state to armed opposition groups vindicating the governmental power over the entire state territory. They differ in the effectiveness of their control of territory and in respect of the type of conflict within which they operate. This can be ongoing armed hostilities or relatively stable frozen conflicts. What is common to all such entities is their ability to control a given area of the territory without the agreement of the recognised government of the state.

Stemming from this territorial control, several legal consequences arise under customary law, international humanitarian law (IH L), international human rights law (IHR L), and refugee law. Furthermore, legal rights and obligations become applicable to the de facto regime, be it a party to an armed conflict under IHL or an entity exercising quasi-governmental powers under IHRL. The question this chapter considers is whether the applicability of such rights and obligations allows for the allocation of a certain role to de facto regimes (DFR s) in the context of the concept of Responsibility to Protect (R2P) as defined in the 2005 World Summit Outcome (WSO) and subsequent UN documents.