ABSTRACT
The use force was one such activity that was engaged in by members of the UN. This Chapter analyses the International Humanitarian Law (IHL) and International Human Rights Law applicability thresholds. The ratione materiae applicability of IHL to Conflicts in which UN forces participate cannot therefore be doubted. The chapter identifies the legal sources as a precursor to ascertaining the regulatory candidates and the relevant behavioural standards. Functional Treaty Succession draws analogies with the theory of State Succession – which subjects succeeding States to the obligations by which their predecessors were last bound. Customary law has been consistently regarded as binding all international actors including the UN. The formation of customary law thus follows what is referred to as the ‘two element approach’ – comprised of state practice in the sense of a rule and such practice being undertaken in the sense of a legal right or obligation.
