The impact of the UN convention against torture and subsequent practice on the law of head of state immunity

Abstract

This thesis examines the current state of international law with regards to the doctrine of immunity for heads of state. In particular, this thesis provides an analysis of the repercussions of the UN Convention against Torture (CAT) on the law of head of state immunity. Much academic writing has supported the view that alleged violations of the prohibition of torture, should lead to the restriction of immunity for heads of state and higher officials for alleged acts of torture. Given the fact that the CAT is silent on the issue of immunity, this thesis investigates whether Articles 1 and 5 of the CAT have become customary international law (CIL). On a theoretical level, this thesis explores this hypothesis by scrutinizing the ‘circularity’ relationship between the Treaty and CIL. This involves treaty interpretation under Articles 31 and 32 of the Vienna Convention on the Law of Treaties [1969]. The purpose of the circularity debate is to determine how the CAT affects CIL, and how CIL affects the interpretation of the CAT in order to ascertain whether Articles 1 and 5 of the CAT have become CIL. On a more concrete level, the thesis examines the evidence, in particular, the opinio juris elements of head of state immunity such as the UNGA Resolutions, and the Committee against Torture. The jurisprudence of ad hoc tribunals also contribute to the understanding of definition of torture and the jurisdiction provisions. This thesis submits that there is conclusive evidence to indicate that Articles 1 and 5 of the CAT have become CIL, and could therefore restrict immunity ratione materiae for former heads of state and heads of government. The claim that the CAT has become CIL is supported by an in-depth analysis of the modern formation of the CIL method under the sliding scale theory. It will be seen that by relying on the subjective element there is no restriction for the claim that new CIL can be formed, provided enough evidence has been provided.