Separation between jus ad bellum and jus in bello as insulation of results, not scopes, of application

This article examines the tendencies to define the scope of application of jus ad bellum negatively in relation to the scope of application of jus in bello and demonstrates their neutralizing effect on the prohibition on the use of force under Article 2(4) of the Charter of the United Nations. It argues that individual acts of use of force during an international armed conflict regulated by jus in bello, whether in combat, in restricting the freedom of enemy nationals or in maintaining an occupation, are equally regulated by jus ad bellum. It clarifies the concept of ‘separation’ between jus ad bellum and jus in bello as the insulation between the results of their respective application, not the differentiation between their respective temporal, material and normative scopes of application. It also addresses the practical concerns raised by this conception of ‘separation’ between jus ad bellum and jus in bello.