Kalshoven, Frits Keywords: Armament | Public international law | Mots clefs: Armements | Droit international public | ABSTRACT After presenting some considerations on the Ius ad bellum, namely the rules governing the use of force by States in the conduct of international relations, the author focuses in detail and in depth on the Ius in bello, namely the rules governing the use of arms during the armed conflict. To allow a better understanding of these rules and principles, the author puts the question in a histo…