The focus of this thesis is the analysis of the legal qualification of international and non-international armed conflicts in the context of changes and challenges of the modern age that the international community is faced with. Namely, the emergence of a variety of armed conflicts, as well as the intertwining of their different features, prompt a revision of the existing legal norms for the regulation of various aspects of armed conflicts. Thus, along with the analyses of the international legal framework embodied in the Geneva Conventions for the protection of the victims of war of 1949 and the Protocols Additional to the Geneva Conventions of 1977, the author explores, through the examples of armed conflicts in Columbia, Iraq and the Lebanese Israeli conflict, the reactions of the international community regarding the specific features of these conflicts, as well as the modalities of adaptation of the existing rules to contemporary circumstances. The aim of this paper is to show how the differences between international and non-international armed conflicts are often blurred in modern age and to examine whether such a differentiation is equally significant in comparison to the circumstances in which the Geneva Conventions and the Additional Protocols were adopted. Lastly, the author proposes the adoption of a new comprehensive international agreement which would consider the challenges of the modern age, particularly those related to the qualification of armed conflicts. The new legally binding instrument would, in the author’s opinion, contribute to the more efficient application of the entire international law of armed conflicts throughout the international community and the better protection of all those affected by armed conflicts.