How is a civil war different from a war between two countries?

A civil war is fundamentally distinguished from an interstate war by the nature of the participants and the location of the conflict.

• Civil War: This is a violent conflict occurring within a single state’s territory between the state and one or more organized non-state actors. These actors may seek to control the central government, pursue territorial secession, or achieve social transformation. Because these are considered internal or noninternational armed conflicts, they are governed by different legal frameworks, such as Article 3 of the 1949 Geneva Conventions, which provides limited protections compared to those afforded in international conflicts.12
• Interstate War: This involves fighting between two or more sovereign states. Unlike internal conflicts, these are classified as international armed conflicts, where the full body of the laws of war applies to combatants and civilians.12

While these definitions are distinct, the two can overlap; civil wars often involve external support for insurgents, and poor relations between countries can lead to one state backing rebels in another, potentially escalating an internal struggle into an international conflict.23