Ethics are central to the vision and pursuit of the good international life in a globalised and highly interdependent system. This is also the case for nuclear weapons. Underlying the struggle for power are ethical contestations over norms and values that define what nation states are.

The balance of power on its own cannot provide a stable global order; it has to be backed by a common set of values and international practices appropriate to these. The shared vision of a good international society, and the ethical principles underpinning it, finds its most authoritative and eloquent articulation as the purposes and principles enunciated in the UN Charter.

Power and principles intersect at the UN and also in regards to nuclear politics. Most countries have chosen nuclear abstinence because people overwhelmingly abhor the bomb. The very destructiveness of nuclear weapons robs them of political and military utility, thereby rendering them immoral.

There are at least eight distinct ethical components to the nuclear debate.

First, nuclear weapons are the most indiscriminately inhumane ever invented. Their lethal destructiveness constitutes an existential threat not just to the leaders, soldiers and citizens of the target country, nor even just the countries fighting a nuclear war, but to all human beings. Indeed a full-blown nuclear war would destroy the Earth. It is hard to see how any human being can claim and exercise the moral right to play God in making such a decision. On the only occasions in which they were used as weapons of war in 1945, no-one really knew of their game changing nature, and historical evidence suggests that the Truman administration viewed them as an incrementally improved weapon of war.

The second ethical concern is that nuclear weapons obliterate the distinction between combatants and civilians that is central to just about every moral code in all cultures and civilisations. It is hard to see how nuclear weapons can be just war compliant with regard to the proportionality and civilian-combatant distinction requirements.

Third, following from this, the doctrine of deterrence, even short of use, proves problematic. The limited utility of deterrence (only romantics and dreamers believe in its absolute utility) rests on the threat of inflicting mass killings on civilians. In 1983 Catholic bishops granted ‘a strictly conditional moral acceptance of deterrence’ in order to protect the independence and freedom of nations and peoples. In December 2014 the Holy See updated the religious prohibition and erased the possession-use distinction to place nuclear deterrence outside morally permissible limits.

Fourth, by fostering a nuclear apartheid the existing nuclear regime fails the test of inter-state equity. Possession of nuclear weapons is compliant with the Nuclear Non-Proliferation Treaty (NPT) for a tiny minority of five countries (China, France, Russia, the United Kingdom and the United States: the N5) and for everyone else it is prohibited. In actual practice however, Israel has never been subjected to normative sanctions by Western powers. Gradually over the past decade many countries have also come round to accepting India and Pakistan (but not North Korea) as de facto nuclear-armed states.

Fifth, countries lack the individual or collective capacity to cope with the humanitarian impacts of a nuclear war. From this it follows that for the sake of humanity’s survival, nuclear weapons must never be used again under any circumstances. And the only guarantee of non-use is total elimination.

Sixth, if the consequences of a nuclear war are systemic, then decisions on arsenals, doctrines and use cannot be solely a matter of sovereign privilege. The same is true with regard to the safety and security aspects of nuclear energy for peaceful purposes. Because a bad accident in one country can have horrific effects in neighbouring countries, people have the moral right to have their voices heard in the decision to build and operate nuclear plants to global safety standards: no incineration without representation.

Seventh, from inception the normative bargain in the NPT has always been that those without nuclear weapons would not pursue that option; all States Parties would cooperate in preventing the spread of nuclear weapons to anyone else; and the five with the bomb would enter into negotiations to get rid of their own weapons. The first part in this three-way equation has been honoured by all countries bar one (North Korea); the second part has been successful except for Israel, India and Pakistan; and the most glaring failure has been with respect to the third legal obligation: nuclear disarmament by the N5. When the NPT entered into force in 1970, there were more than 38,000 nuclear warheads in the world, with just over 26,000 in the US arsenal and under 12,000 in the Soviet stockpile. Sixteen years later, these numbers had climbed to over 64,000 (global), 24,000 (US) and 40,000 (Soviet Union). Spokesmen from the N5 perform Olympic-quality verbal gymnastics in explaining how this was in conformity with their disarmament obligation under Article VI of the NPT. Of course, not a single one of them has disarmed even now.

The latest NPT review conference collapsed in failure last May. This is further evidence that the treaty has exhausted its normative potential in containing and eliminating the nuclear threat. All countries that have them betray — through stockpiles, expanding numbers, modernisation and upgrades already underway or planned, doctrines, force postures and deployment practices — the intention to retain them indefinitely as an anchor of national security.

This then raises the final moral dilemma. Tom Doyle of Texas State University asks: At which point do non-nuclear weapon states conclude that defection from the NPT regime is likely to be politically effective, is morally permissible and may in fact be the ethically responsible course of action?

An analogous situation is with membership of a club that discriminates on grounds of race, religion, gender or sexual orientation. One can remain a member or even join in order to try and change the membership rules from the inside. But if efforts fail over many repeated attempts, at some point the decision has to be made to resign or become morally compromised with respect to one’s own ethical code.

Professor Ramesh Thakur is director of the Center for Nuclear Non-Proliferation and Disarmament, Crawford School of Public Policy, Australian National University. This article is adapted from an article that appeared in The Japan Times on 10 February.