In recent years the debate on outlawing nuclear weapons has (re)emerged. By naming personal experienced events, I have tried to summarize this issue - which, in my point of view, has a strong normative ethical componant.
In the bold discussions on the NPT and its review process, some states argue with legal and normative obligations not to use nuclear weapons. The non-Alignement Movement (NAM) and the New Agenda Coalition (NAC) stated that the use of nuclear weapons would violate IHL and the UN Charter. Some others reiterated their commitment to including discussion of IHL in the NPT. The NWS did not like this approach: The UK argued that the International Court of Justice “rejected the argument that use of nuclear weapons would necessarily be unlawful in all circumstances.” The US also, somehow rejected the view of illegality of nuclear weapons by stating that “A serious analysis of the legality of a hypothetical use of nuclear weapons would have to consider the precise circumstances of that use, and cannot be evaluated in the abstract.”
Non-use of nuclear weapons
The debate among policy makers, scholars and others on whether or not nuclear weapons would be used is –to a great deal- determine by whether or not it could be used. For a nuclear weapon state, in order to realize bargaining gains, it has to make sure the salience (the probability of them being used) in not null – in order to keep the factor of deterrence alive. To do so, it is necessary to indicate that nuclear weapons could indeed be used. Beside the fact that the net benefits may have always been low, there are developments that could make it more challenging for nuclear weapons state to keep the salience well above null. It can be argued that using the bomb has become an absolute taboo. It is an international norm that using the bomb is unlawful. “While the costs of the maximum-escalation scenarios will increase in the shadow of nuclear weapons, the associated probabilities should decrease.” This can be described by the costs of breaking norms.
There are certain normative constrains attached to nuclear weapons. International law, International Humanitarian Law, norms of non-use and/or the nuclear taboo have decreased salience of nuclear weapons being introduced to a conflict.
However the reason why nuclear weapons are somehow singled out as not useable is not necessarily the fact that they are so destructive, since we now have weapons that are as destructive as nuclear weapons. It is rather that there is a certain norm attached to nuclear weapons specifically. A norm that many NNWS want to crystalizing into international (humanitarian) law, whereas NWS states ague that it would not apply under all circumstances, while noting the humanitarian catastrophes devoted to these weapons.
The nuclear taboo –not necessarily implemented into international humanitarian law- which may be held responsible for the lack of use of nuclear weapons over the last several decades, exists even if it is not as widely accepted as it once was, and most notably, does not have the overarching magnitude in the international public.
No need to address illegality of nukes specifically
I have recently attened a Seminar by the Vienna Center for Disarmament and Non-Proliferation, with Justice Weeramantry as the keynote speaker. Justice Weeramanty was a Judge of the ICJ, when ICJ delivered an advisory opinion, in 1996, about the Legality of the Threat or Use of Nuclear Weapons (mentioned above). The decision provides one of the few authoritative judicial decisions concerning the legality under international law of the use or the threatened use of nuclear weapons. Judge Weeramantry's presentation focused on the obligation under Article VI of the NPT for the nuclear-weapon States, and all other States, to pursue negotiations in good faith on ending the nuclear arms race and achieving nuclear disarmament, as well the issue of nuclear weapons in international law and their humanitarian consequences.
Weeramantry based all his arguments on four main grounds;
In his introduction Weeramantry made clear that it is totally irresponsible not to abandon nuclear weapons since with know about their consequences.the keynote speaker.
He also asserted that nuclear weapons violate international law, specifically referring to obligations to protect non-combatants, neighboring countries, civilians, women, children, future generations, and the environment. Therefore, he argued, under the general principles of international (humanitarian) law, the use or threat of use of nuclear weapons is illegal.
Further he sees general peace education as a way forward and that it is not necessary to argue on the bases of International Humanitarian Law, since nuclear weapons also oppose International Law as such. But unfortunately in the cast vote (seven in favour and seven voted against) of the decision of 1996 a window was kept open by stating “that in view of the current state of international law, and of the elements of fact at its disposal, the Court cannot conclude definitively whether the threat or use of nuclear weapons would be lawful or unlawful in an extreme circumstance of self-defence, in which the very survival of a State would be at stake”, whereas Justice Weeramantry hinted that because it says “current status”, the opinion can be demanded again be asking the ICJ to clarify the current situation. Something some states are thinking of doing.
 Beardsley and Asal 2009, 281.