The Common Problem: Weapons of Mass Destruction and Anticipatory Self-defence in International Law

Abstract: The aim of this essay is to analyse the extent of anticipatory self-defence and how it is affected by the presence of weapons of mass destruction. As such, it will provide a summary of current law through doctrine, case law, and the treaties concerning the interpretation of article 51 of the UN Charter. Differing arguments will be illustrated with the help of examples, such as the Israeli attacks, which constitutes waypoints of the discussion of immediacy of a threat for an attack. The essay researches the possibility to ban nuclear weapons and how weapon of mass destruction affects the rules of war, the jus ad bellum, and the notion of anticipatory self-defence. The notion of anticipatory self-defence is controversial within the stage of international security and peace, especially from the perspective of the involvement of nuclear weapons or other weapons of mass destruction. Currently there is no absolute prohibition of nuclear arms, in comparison to chemical and biological weapons, and there might not be for a foreseeable future due to the stubbornness of states that possess nuclear arms. Different arguments about the lawfulness of nuclear arms have been discussed in the light of the ICJ advisory opinion Legality of the Threat of Use of Nuclear Weapons. Despite its disconnection with international humanitarian law, the Court could not rule out its lawfulness as an act of self-defence under extreme circumstances. A general prohibition of production and use of nuclear weapons could therefore not be established. Jus ad bellum is still obligatory rules, notwithstanding the effect WMDs have had on them. The notion of anticipatory self-defence seems to be accepted as lawful practice through both state practice and opinio juris in some cases. Its extent, however, is highly controversial, with questions arising from the prerequisites of immediacy and proportionality. Written law or an international consensus is therefore needed to truly reach the reputation required to be considered customary law. The lawfulness of pre-emptive self-defence is however more controversial and are even further from reaching an agreement within the international community.