The United Nations has regularly observed that proliferation of nuclear, chemical and biological weapons constitutes a threat to international peace and security. Nuclear weapons are explosive devices whose energy results from the fusion or fission of the atom. Nuclear weapons create devastation of unprecedented levels.

The recent nuclear testing by North Korea has invited widespread condemnation from the world community. In resolution 2375 (2017) dated 11 September 2017 the United Nations Security Council observed that such tests challenge the Treaty on Non-Proliferation of Nuclear Weapons and international efforts aimed at strengthening the global regime of non-proliferation of nuclear weapons. It spoke of the danger it poses to peace and stability. The resolution lamented that North Korea continue to develop nuclear weapons and ballistic missiles by diverting critically needed resources away from its own people. It further observed that the ongoing nuclear related activities have destabilized the region and beyond and such developments on the Korean Peninsula could have dangerous, large-scale regional security implications.

Thus the United Nations Security Council acting under Chapter VII of the Charter and taking measures under Article 41 condemned the nuclear test conducted by North Korea on 2 September 2017 in violation and flagrant disregard of the Council’s earlier resolutions and iterated its decision that North Korea shall not conduct any further launches that use ballistic missile technology, nuclear tests, or any other provocation and also shall immediately suspend all activities related to its ballistic missile programme and re-establish its pre-existing commitments to a moratorium on all missile launches as well as abandon all nuclear weapons and existing nuclear programmes in a complete, verifiable and irreversible manner, and immediately cease all related activities; and shall abandon any other existing weapons of mass destruction and ballistic missile programs.

In the Nuclear Tests Case (Australia v. France) (1974, ICJ) France carried out multiple atmospheric tests of nuclear devices at its centre in French Polynesia in 1966-72 which was objected to by Australia on the ground that the French tests had caused fall-out to be deposited on Australian territory. But before the Court could pronounce the judgment France made public its intention to cease conduct of atmospheric nuclear tests following the conclusion of the 1974 series of tests.

The Court took into consideration official statements made on behalf of France concerning future nuclear testing. As declarations made by way of unilateral acts concerning legal or factual situations may have the effect of creating legal obligations when it is the intention of the State making the declaration that it should become bound according to its terms, that intention confers on the declaration the character of a legal undertaking, the State thereafter being legally required to follow a course of conduct consistent with the declaration.

France having undertaken to hold no further nuclear tests, the objective of the applicant had already been accomplished and the Court declined to give judgment. In its order dated 22 September 1995 in Request for an examination of the Situation in Accordance with paragraph 63 of the Court’s Judgment of 20 December 1974 in The Nuclear Tests (New Zealand v. France) case, the ICJ held that as the Court in the 1974 judgment had reached the conclusion it dealt exclusively with atmospheric nuclear tests, it was not possible to take into consideration questions relating to underground nuclear tests. Thus as the basis of the Judgment delivered in the Nuclear Tests (New Zealand v. France) case was not affected, the “Request for an Examination of the Situation” submitted by New Zealand was dismissed.

In the Obligations Concerning Negotiations Relating To Cessation Of The Nuclear Arms Race And To Nuclear Disarmament (Marshall Islands v. India) (2016, ICJ) Marshall Islands argued that India and certain other nations had violated and continued to violate international obligations under customary international law by failing to pursue in good faith and bring to a conclusion negotiations leading to nuclear disarmament in all its aspects under strict and effective international control, in particular by engaging in a course of conduct contrary to the objective of nuclear disarmament. But the court observed that the questions of the existence of and extent of customary international law obligations in the field of nuclear disarmament were not crystallised and in the absence of a dispute the conditions for the Court’s jurisdiction were not met.

Is the threat or use of nuclear weapons in any circumstance permitted under international law? The ICJ in its 1996 Advisory Opinion on the Legality of the Threat or Use of Nuclear Weapons observed that merely because this question has political aspects does not suffice to deprive it of its character as a “legal question” and thus can be looked into by the court. (referring to Application for Review of Judgement No. 158 of the United Nations Administrative Tribunal, Advisory Opinion, ICJ, 1973). The world court referred to its earlier opinion Interpretation of the Agreement of 25 March 1951 between the WHO and Egypt (1980) wherein it was observed that in situations in which political considerations are prominent it may be particularly necessary for an international organisation to obtain an advisory opinion from the Court as to the legal principles applicable with respect to the matter under debate.

Many nuclear states objected to the ICJ’s hearing of the matter. United States objected stating that ‘the question presented is vague and abstract, addressing complex issues which are the subject of consideration among interested States and within other bodies of the United Nations which have an express mandate to address these matters. An opinion by the Court in regard to the question presented would provide no practical assistance to the General Assembly in carrying out its functions under the Charter. Such an opinion has the potential of undermining progress already made or being made on this sensitive subject and, therefore, is contrary to the interests of the United Nations Organization.’

There are various provisions in international conventions which can be utilised for contending that nuclear testing may be against the fundamental principles of international law. Article 6 of the International Covenant on Civil and Political Rights (ICCPR) declares that every human being has the inherent right to life and it is protected by law. No one can be arbitrarily deprived of his/her valuable life. The court refused to accept the contention that the prohibition against genocide, contained in the Convention of 9 December 1948 on the Prevention and Punishment of the Crime of Genocide, can be utilised to declare nuclear weapons against the customary international law.

The court observed that the prohibition of genocide would be pertinent only if the recourse to nuclear weapons did indeed entail the element of intent towards a group as such and thus it would only be possible to arrive at such a conclusion after having taken due account of the circumstances specific to each case. The world court observed that nuclear weapons release not only immense quantities of heat and energy, but also tremendous radiation. The first two causes of damage are vastly more powerful than the damage caused by other conventional weapons. Also radiations render the nuclear weapon potentially catastrophic.

As the destructive power of nuclear weapons cannot be contained in either space or time, it has the potential to destroy all civilization and the entire ecosystem of the planet. Article 2, paragraph 4 of the UN Charter declares that the threat or use of force against the territorial integrity or political independence of another State or in any other manner inconsistent with the purposes of the United Nations is clearly prohibited. But this prohibition on the use of force has certain limitations like Article 42 which allows the Security Council to take military enforcement measures in conformity with Chapter VII of the UN Charter.

Also Article 51 recognizes the inherent right of individual or collective self-defence. But self-defence has certain limitations like the conditions of necessity and proportionality. This is now a rule of customary international law (In the case concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America)(1986, ICJ)).

The ICJ has observed that the proportionality principle may not in itself exclude the use of nuclear weapons in selfdefence in all circumstances. As per the policy statement of the United States various factors are considered to judge whether an armed attack is imminent like the nature and immediacy of the threat, the probability of an attack, whether the anticipated attack is part of a concerted pattern of continuing armed activity, the likely scale of the attack and the injury, loss, or damage likely to result therefrom in the absence of mitigating action and the likelihood that there will be other opportunities to undertake effective action in self-defense that may be expected to cause less serious collateral injury, loss, or damage.

The Court observed that international customary and treaty law does not contain any specific prescription authorising the threat or use of nuclear weapons or any other weapon in general or in certain circumstances, in particular those of the exercise of legitimate self defence. Nor, however, is there any principle or rule of international law which would make the legality of the threat or use of nuclear weapons or of any other weapons dependent on a specific authorisation. Unfortunately there has been strong divergence of opinion among countries on the matter whether nonrecourse to nuclear weapons over the past 50 years constitutes the expression of an opinio juris. There is an important series of General Assembly resolutions that deal with nuclear weapons and that affirm, with consistent regularity, the illegality of nuclear weapons.

General Assembly resolutions may sometimes have normative value. After examining the General Assembly resolutions in detail, the Court declared that the use of nuclear weapons would be “a direct violation of the Charter of the United Nations’ and in certain formulations that such use “should be prohibited”. But very often several resolutions have been adopted with substantial numbers of negative votes and abstentions which clearly indicate that they still fall short of establishing the existence of an opinio juris on the illegality of the use of nuclear weapons.

Though the adoption of large number of resolutions requesting the member States to conclude a convention prohibiting the use of nuclear weapons in any circumstance, reveal the desire of a very large section of the international community to take, by a specific and express prohibition of the use of nuclear weapons, a significant step forward along the road to complete nuclear disarmament, yet the emergence, as lex lata, of a customary rule specifically prohibiting the use of nuclear weapons as such is hampered by the continuing tensions between the nascent opinio juris on the one hand and the still strong adherence to the practice of deterrence on the other. Thus there is in neither customary nor conventional international law any specific authorisation of the threat or use of nuclear weapons, but there is in neither customary nor conventional international law any comprehensive and universal prohibition of the threat or use of nuclear weapons as such.

The ICJ held that it could not definitively conclude “whether the threat or use of nuclear weapons would be lawful or unlawful in an extreme circumstance of self-defense, in which the very survival of a State would be at stake.” Though weapons of mass destruction are declared illegal by specific instruments, complete nuclear disarmament still eludes us. Awarding of the 2017 Nobel Peace Prize to the International Campaign to Abolish Nuclear Weapons (ICAN), a coalition of nongovernmental organizations committed to nuclear disarmament is a welcome step.

Passing of the Treaty on the Prohibition of Nuclear Weapons, the first legally binding international agreement to comprehensively prohibit nuclear weapons, in July 2017 clearly suggests that the final days of nuclear arsenals may be coming closer. The writers are Mumbai-based advocates and legal consultants.