Internal armed conflict can be defined as the use of armed force within the boundary of one state between one or more armed groups and the acting government, or between such groups. Different terms can cover such situations: rebellion, revolution, internal disturbances, violence, terrorism, guerrilla warfare, resistance, internal uprising, civil war, war of self-determination … These terms depict the scale, the various levels of intensity of a conflict, or express for some of them the method of combat, such as guerrilla warfare, or the goal of the conflict, such as war of self-determination. They all carry a certain political weight and some fall within the legal category of internal armed conflict. Whereas certain scholars have studied the concept of internal armed conflict by looking at the causes of such conflicts, international lawyers have started to define the concept of internal armed conflict when international law was deemed to regulate some aspects of such conflicts. The 1949 Geneva Diplomatic Conference on the laws of war established the modern distinction between international armed conflicts, replacing the old concept of war, and internal armed conflicts, defined as a conflict of a non-international character. Prior to that date, it had been generally agreed that it was the sovereign right of each government in power to maintain internal order and ‘to punish the insurgents in accordance with its penal laws’.