How is the term “armed conflict” defined in international humanitarian law?

International humanitarian law (IHL) applies to situations of armed conflict, a de facto state of hostilities dependent on neither a declaration nor recognition of the existence of “war” by its parties. In terms of its material scope, whether an armed conflict is an international armed conflict (IAC) or non-international armed conflict (NIAC) will largely determine which rules of IHL apply. Articles 2 and 3 common to the Geneva Conventions differentiate between the rules applicable to IACs and NIACs. However, the term “armed conflict” is defined in neither article. Far from being an oversight, the omission plays an important role in depoliticizing the application of the Conventions to the situations of violence for which they were conceived. Having learned from earlier reliance on notions such as “declarations of war”, the drafters’ choice of the notion of “armed conflict” ensured that the Conventions’ catalyst would never become a vestige of its time, but rather a concept meant to endure and, indeed, adapt in response to the changing environments for which the Conventions are needed. The application of IHL has since been predicated on a fact-based analysis rather than only the formal recognition by a belligerent that a state of war exists.