According to the International Committee of the Red Cross (ICRC), a civil war refers to armed conflicts occurring within the borders of a state between governmental forces and organized non-state armed groups, characterized by a certain level of intensity and protracted violence. In such conflicts, non-state actors must demonstrate a clear command structure, the capacity for coordinated military operations, and a minimum number of combatants. Civil war is thus distinguished from acts of terrorism, uprisings, or revolutions by its structural features rather than its underlying causes. For instance, the conflict in Syria was classified as a civil war by the ICRC in 2012, whereas the large-scale violence in Iraq after 2006 did not meet these criteria and was not categorized as such.

• International Committee of the Red Cross (ICRC). (2008). How is the Term “Armed Conflict” Defined in International Humanitarian Law? Opinion Paper.
• Sambanis, N. (2004). What Is Civil War? Conceptual and Empirical Complexities of an Operational Definition. Journal of Conflict Resolution, 48(6), 814–858.
• Kaldor, M. (2013). New and Old Wars: Organized Violence in a Global Era. Polity Press.
• European Union Institute for Security Studies. (2013). What is a Civil War?. Retrieved from https://ciaotest.cc.columbia.edu/pbei/weu/0029419/f_0029419_23869.pdf