In spite of all the existing rules of law, many armed conflicts continue to break out in certain States, causing considerable human suffering and material damage, as in the Democratic Republic of Congo.Millions of civilians see their lives shattered by these armed conflicts, which are often accompanied by serious violations of international law. Taking into account the fact that these armed conflicts must be resolved and eradicated, it is urgent to analyze their criteria of qualification, the applicable rules as well as the multifaceted legal contours.This book is particularly interested in demonstrating that it is not always easy to qualify a situation as an armed conflict without analysing all the different categories that can be interpreted in view of the theoretical approaches linked to the evolution of international legal practice.