Evidence of catastrophe

Background Papers

A summary of the facts presented at the three conferences on the humanitarian impact of nuclear weapons

1 May 2015

During 2013 and 2014, three conferences have been organized in Oslo, Nayarit and Vienna as part of an initiative to highlight the humanitarian impact of nuclear weapons. The conferences have gathered representatives of States, UN organisations, the International Red Cross and Red Crescent Movement, academia and civil society for facts-based discussions about the humanitarian consequences and risks associated with nuclear weapons. The purpose of this publication is to summarise and disseminate the insights presented to the three conferences on the humanitarian impact of nuclear weapons. [1]

Background Paper No 15/2015 Published: May 2015

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A nuclear detonation

A nuclear detonation unleashes a massive amount of energy due to a nuclear chain reaction involving either a fusion of hydrogen isotopes, a fission of plutonium or uranium atomic nuclei, or both. When a nuclear weapon detonates, the energy released immediately produces an intense flash and a huge fireball reaching several thousand degrees Celsius at the centre.[2]

Within a fraction of a second, the fireball produces a shock wave, violent wind gusts of several hundred kilometres per hour,[3] and an immense overpressure. The extreme heat of the fireball also emits ionising radiation, i.e. radiation with enough energy to change the internal structure of atoms and molecules in surrounding objects, and is followed by a wide-ranging electromagnetic pulse.

After the shock wave has passed, radioactively contaminated dust and ash from the initial explosion start to fall to the ground, producing nuclear fallout. These particles can be transported by winds to areas hundreds of kilometres away from the point of detonation, thus creating a wide area of radioactive contamination.[4]

Humanitarian impact

The detonation of a nuclear weapon would have serious immediate and longer-term consequences for people, society and the environment. While the full extent of these consequences depends on several factors, including the size, number, height and location of the explosion(s),[5] it is possible to make some general predictions on the basis of past experience and accumulated knowledge.

Immediate humanitarian consequences

The detonation of a nuclear weapon in a populated area would have serious immediate humanitarian consequences. Depending on the size and location of the detonation, as well as other factors such as weather conditions, tens or even hundreds of thousands of people could be killed or seriously injured by the flash, heat and fire, direct and indirect effects of the shock wave as well as by ionising radiation.[6]

Heat and fire

No one at or around ground zero of the fireball created by a nuclear detonation would survive the heat. Depending on the explosive yield of the weapon, the ensuing flash of heat radiation could cause severe burns and flash blindness as far as twenty kilometres from the point of detonation.[7] Houses, forests and other flammable objects in a potentially much larger area are likely to catch fire, with the wind gusts produced by the shock wave feeding a deadly firestorm. If the nuclear detonation occurs in a populated area, a very large number of people would, as a consequence, be expected to require immediate treatment for serious burns.[8]


The shock wave and associated high-speed wind gusts caused by a nuclear detonation would flatten buildings and instantaneously kill people within a large area.[9] After the bombing of Hiroshima, displaced roof tiles were found as far as eight kilometres from the point of detonation. Within a radius of several kilometres from ground zero of a nuclear detonation, therefore, people would suffer from multiple traumas and other injuries caused by falling buildings, shattered glass and other potentially lethal flying objects.

Ionising Radiation

Exposure to the high dose of ionising radiation produced by a nuclear detonation would cause acute radiation syndrome (ARS).[10] This may be lethal, with death occurring within days or weeks. In the immediate term, ionising radiation exposure would cause suppression of the immune system and decreasing resistance to infections, hence exacerbating the impact of other injuries caused by the nuclear detonation. It may also cause systemic failure in the human body and lead to the destruction of bone marrow, as well as damage to the heart and blood vessels, the stomach and intestines, and the central nervous system.[11]

In addition to the immediate radiation, radioactive fallout is likely to affect a large area. In the case of a ground-burst detonation, debris will be drawn into the fireball and spread in a cigar-shaped area down-wind. People living in or around this area may be exposed to deadly doses of radiation.[12]

Damage to the infrastructure

The blast and fire produced by a nuclear detonation would cause serious damage to critical infrastructure. An event of the magnitude caused by the detonation of a nuclear weapon would pose extraordinary challenges for even a well-stocked, fully operational health system. Indeed, any scenario involving the detonation of a nuclear weapon over a city centre would likely result in the devastation of that city’s health services, which could be rendered completely unusable for the indefinite future.

Medical personnel are likely to be among the victims, and those not injured might not return to work due to risks associated with radiation or because of disruption to transportation networks and other intervening infrastructure. Those medical institutions still functional would, as a consequence, likely be seriously understaffed. According to the ICRC Resource Centre, of the health personnel in Hiroshima, 270 out of 300 doctors were killed or injured and 1654 out of 1780 nurses.[13]

Damage to roads, the electrical grid, communication networks and supply chains caused by the electromagnetic pulse, as well as contamination of water supplies, food and other necessary items would make it difficult to sustain any activity in affected areas, not least medical assistance to thousands or millions of injured people.

Long-term humanitarian consequences

The full social and economic impact of a nuclear weapon detonation is difficult to gauge, as many different scenarios are conceivable. There is, moreover, a limit to the extent to which historical experience is instructive for understanding the full, global consequences of a nuclear weapon detonation today. This is, among others, because most nuclear weapons in current arsenals are far more powerful than those previously used. Our contemporary world is also far more integrated and interdependent than it was in 1945, or even during the Cold War.

Cancer, leukaemia, congenital malformation

Exposure to ionising radiation damages chromosomes, with multiple longer-term effects on reproductive health, including congenital malformations, loss of fertility, miscarriages and spontaneous abortions. Radiation exposure also significantly increases the likelihood of developing cancer.[14] Children are particularly vulnerable to radiation because their bodies are small and their cells are naturally dividing. Among the survivors of Hiroshima and Nagasaki, surviving children who were five years or younger in 1945 were the most likely to get cancer during their lifetime. There were also significant gender differences, with girls twice as likely to get cancer as boys and with women exposed as children 50 per cent more likely to get cancer.[15]

According to a study on the consequences of nuclear testing conducted at the Semipalatinsk test site in Kazakhstan, the health consequences of exposure to radiation can be divided into the following three time-based categories:[16]

1-10 years from the start of radiation:

  • High infant mortality.
  • Congenital malformations among children.
  • Frequency of leukaemia as a major cause of death among children. The frequency doubled compared to the period 1945-48.

10-20 years from the start of radiation:

  • A dramatic increase in mortality from cancer, up to 3.5 times higher than in the control group, and in Kazakhstan as a whole.
  • Malformations among the children of women exposed to radiation in childhood.

20+ years from the start of radiation:

  • Increase in the incidence of cancer, up to three times higher than in the control group, and in Kazakhstan as a whole.
  • Premature aging and reduced life expectancy.

Post-traumatic stress disorder, depression, survivor’s guilt

The detonation of a nuclear weapon would have a profound psychological impact on those in and around affected areas. One lasting legacy of the nuclear attack on Nagasaki was a heightened incidence rate of post-traumatic stress disorder (PTSD) and depression in areas close to ground zero.[17] People exposed to ionising radiation from the tests conducted in Kazakhstan have exhibited similar symptoms, with uncertainty about the health impacts of radiation and the perceived risks having detrimental psychological effects on people in affected areas.[18]

Survivors will have experienced a deeply traumatising event that could include the loss of loved ones, a prolonged period or even life-long uncertainty over the state of their own health, and profound feelings of abandonment or guilt of having survived while family and friends died. Survivors have also experienced discrimination and stigma, such as difficulty finding a job or spouse, due to ignorance or misconceptions about the effects of radiation.[19]

Food safety and agriculture

The detonation of a nuclear weapon would result in widespread radioactive contamination, which in turn could render many sources of food and water useless. Although the extent of the contamination would depend on a number of topographic and meteorological conditions, it is clear that any clean-up process would be very expensive, and possibly not even feasible.[20]

Radioactive fallout could make large areas unsuitable for food production for a very long time. Depending on the explosive yield of the warhead, the location of the explosion and other conditions specific to the incident, radioactive fallout might affect several countries, or even whole regions.[21] For any country or region that experiences the detonation of a nuclear weapon, an immediate, and possibly lasting, need for greater food imports is a likely outcome. This could increase national, regional and even global food prices. For the poor and those already suffering from chronic malnutrition this could have very serious consequences, since these groups are highly vulnerable to increases in food prices.[22]


Those living in an area struck by a nuclear weapon would face the risk of radiation, as well as significant infrastructural damage. This would likely lead to massive displacement, with survivors migrating to safer places within an across borders.[23] Many survivors would have lost their homes and livelihoods and would require food, water, shelter and medical attention for a significant period of time.

Lingering questions over radiation risk and a lack of infrastructure could persist and inhibit the return of former inhabitants, who may instead become permanently displaced, requiring long-term assistance and support. Agricultural disruption and food shortages could also increase the risk of conflict, as communities may have to compete over food and water.[24]

Former Norweigan Minister of Foreign Affairs, Espen Barth Eide, speaking to the first conference on the humanitarian impact of nuclear weapons, in Oslo, Norway, 4-5 March 2013 (Photo: Torbjørn Graff Hugo/ILPI).

Former Norweigan Minister of Foreign Affairs, Espen Barth Eide, speaking to the first conference on the humanitarian impact of nuclear weapons, in Oslo, Norway, 4-5 March 2013 (Photo: Torbjørn Graff Hugo/ILPI).

Economic disruption

The detonation of a nuclear weapon would likely lead to massive destruction of property, in addition to damage to productive capacities, infrastructure and the communication networks that enable modern commerce. The resumption of economic activity in the affected areas would be a slow and expensive endeavour. Almost thirty years after the accident at the Chernobyl nuclear plant, the affected areas still experience higher levels of poverty than neighbouring regions in Ukraine, Russia and Belarus.[25] Studies from Chernobyl and Semipalatinsk show that investment is still limited, infrastructure lacking and many young people abandon the areas due to the lack of opportunities.[26]

At a time when global markets are deeply integrated, any event that disrupts economic activity in one country can have global economic ramifications. The destruction, disruption and fear resulting from the detonation of even a single nuclear weapon in any large city could have severe national and international consequences.

While a single nuclear detonation would have a range of devastating immediate and long-term humanitarian consequences, the impact of a war involving several nuclear detonations would have an additional set of long-term consequences for the global climate, affecting food production, agriculture and the environment.

Research has shown that in scenarios involving the detonation of only 1 per cent of the current global nuclear arsenal, the resulting firestorms would produce massive amounts of sooty smoke. This would rise so high into the atmosphere that it could not be rained out, thus spreading around the globe where it would remain for years or decades. The result would be decreased sunlight reaching the ground, colder temperatures and less rainfall. The effects would be long-lasting, to a large extent due to the cooling of the oceans (creating climate-thermal inertia) and dramatic sea-ice expansion. [27]

In the aftermath of a nuclear exchange, the climate would be cold, dry and dark—a scenario often referred to as a “nuclear winter”. Decreased sunlight, colder temperatures and less rainfall would have serious consequences for global production of staple crops such as rice and maize, on which millions of people depend, putting them at risk of mass starvation. As an example, a regional nuclear war producing 5 million tons of smoke would result in a decrease of maize production in the United States by 20 per cent the first five years, and 10 per cent the second five years, while the decrease of maize production in China would be 20 per cent and 15 per cent.[28]. Colder temperatures would cause a shortened frost-free growing season and cold spells during the growing season, which would entail slower growth and lower yield. Darkness and less rainfall would also affect agriculture. There are further anticipated consequences on agriculture, not yet modelled, such as lack of water supply, fertilizer, seeds, pesticides and fuel for machinery.[29]

A nuclear exchange could also cause unprecedented ozone loss, which would affect human health by leading to rapid sunburns and an increase in skin cancer. Other effects include damages to crops and eco-systems on land and in the oceans. The combined effects of elevated UV levels on agriculture and marine ecosystems could also have a significant impact on global food security, as more than 30 per cent of animal protein consumed by humans comes from the sea.[30]

A nuclear war using less than 1 per cent of the current nuclear arsenal would produce a climate change that is unprecedented in human history.

Preparedness and response

Both the International Committee of the Red Cross (ICRC) and the United Nations (UN) have conducted studies concluding that it would not at present be possible to mount an effective humanitarian response to a nuclear weapon detonation. These findings reflect the view that the detonation of a nuclear weapon represents unique challenges for preparedness and response.

Overwhelming needs

The sheer magnitude of the destruction and the number of victims represent the biggest challenges confronting those expected to provide humanitarian assistance in the event of a nuclear weapon detonation. Providing adequate, timely and appropriate assistance to hundreds of thousands or even millions of people would require enormous amounts of manpower, material resources and logistical capacity.

The ICRC considers that no organisation on its own possesses sufficient resources to ensure an effective response to such a humanitarian crisis, and that it would necessitate cooperation among multiple actors. Such cooperation is presently complicated by the lack of a common understanding of what would be needed to address the humanitarian consequences of a nuclear weapon detonation.[31] A UN study on the challenges of nuclear weapon detonations for humanitarian coordination and response concludes that the UN is unlikely to be able to offer coordinated humanitarian assistance in the immediate aftermath of a nuclear weapon detonation event. Responding to a nuclear weapon detonation event would be anything but “business as usual”, and current planning and approaches to humanitarian response may not be applicable.[32] The humanitarian system is not geared towards responding to the unprecedented destructive force and radiological impact of a nuclear detonation and it has no prior experience on which to draw on should it occur.[33]

Extreme logistical challenges

In order to provide relevant assistance, humanitarian organisations would have to be present on the ground immediately after the detonation of a nuclear weapon. Dangerous radiation may however preclude this, as these organisations would have to balance the requirements of their humanitarian mission against the risks they are exposing their own personnel to. The threat of further detonations could also vastly complicate humanitarian decision-making.

The deployment of external resources would also require dependable transport and other logistics capacities. Whether this would be forthcoming in the event of a nuclear weapon detonation is an open question. Another question is whether states would allow passage for military assets intended for assistance purposes.[34]

Limited national capacity

Existing international humanitarian assistance capacities are geared towards assisting national authorities.[35] The adequacy and appropriateness of assistance given to survivors of a nuclear weapon detonation would largely depend on the extent to which national authorities are able to respond and what level of national capacity that remains.

Depending on the circumstances, the detonation of a nuclear weapon could severely undermine the ability of national authorities to operate. Critical staff might be dead, injured or otherwise incapacitated due to the detonation. Additionally, infrastructure required for communication and coordination could be destroyed, and the emergence of fear about radiation or further nuclear weapon detonations could lead to absenteeism. In any of these scenarios, those parts of national authorities still operating are likely to be overwhelmed by the urgent needs of their populations and the health-, emergency response systems and infrastructure would be paralysed or severely incapacitated.

Emergency planning for an event involving the detonation of a nuclear weapon is further complicated by the possibility that it may take place in the context of an on-going armed conflict. Those expected to provide humanitarian assistance under such circumstances would have to consider the possibility of further nuclear weapon strikes, or other acts of war.[36]

Contingency plans at national level

The possibility of a nuclear weapon detonation requires both prevention and preparedness to respond. As working to prevent is in no manner a guarantee that a nuclear detonation will not occur, preparation to respond is essential. Informed planning and decision-making can save lives and reduce harm in the event of a nuclear weapon detonation.[37]

Most countries have some contingency plans in place for dealing with nuclear and radiological incidents. Such events may include accidents at domestic or foreign nuclear facilities, as well as contingencies involving mobile sources (e.g. nuclear submarines) or release of radiation into the air or the maritime environment. Countermeasures typically include evacuation, decontamination and sheltering of affected populations, as well as early medical response and steps to secure contaminated areas.[38] Evacuation is critical—especially the first hour, survivors must know where to go. Authorities must also collect and analyse data to predict and map the fallout zones. Guidance must be communicated quickly and effectively to the public. Such countermeasures are, however, likely to fall short of actual humanitarian needs in the event of a nuclear weapon detonation. And it is currently unlikely that such a response would be well executed, even in the best-prepared cities. Communication possibilities are uncertain, movement would be severely constrained and there is inadequate knowledge about what infrastructure would still be effective.[39]

Human, financial and material resources allocated for emergency preparedness purposes are, in most countries, limited. Few, if any, countries have capacities in place that could adequately respond to the humanitarian consequences of a nuclear weapon detonation in a populated area.

This lack of resources is compounded by the fact that the location of a nuclear weapon detonation is not easily predictable. Unlike a nuclear power plant, a nuclear warhead is mobile. The list of possible targets or sites where an accident could take place is almost unlimited. This makes it hard to plan properly for emergency response. It could ultimately be futile and also prohibitively expensive to invest in pre-designed evacuation routes, sites for decontamination and shelters for every person that could potentially be affected.[40]


For as long as nuclear weapons exist, the risk of an inadvertent, accidental or intentional nuclear detonation remains.

Risk is normally defined as the probability that an event will occur multiplied by the consequence of that event occurring. The risk of use of nuclear weapons can therefore be defined as the probability of use multiplied with the expected impact of one or more nuclear weapon detonations.[41]

The longer we wait, the more likely nuclear war is to occur.[42]

The probability of use of nuclear weapons is higher than zero, and therefore significant. The probability of an intentional or inadvertent nuclear exchange has been calculated to lie somewhere between once per 15 years to once per 100,000 years, and the probability increases over time.[43] Although the probability of use of nuclear weapons is low, in light of the massive and system-wide scale of the humanitarian consequences of nuclear weapons, the risk of a nuclear detonation is generally considered to be high.

Near misses

The fact that the probability of use of nuclear weapons is higher than zero is evidenced by a series of incidents of near nuclear weapons use. One such incident described in Vienna involved an accidental breakdown of a 52-Bomber carrying a hydrogen bomb over North Carolina in the United States in 1961. The bomb went through a series of arming steps while falling to the ground, and only one switch in that weapon prevented a nuclear detonation in North Carolina hundreds of times more powerful than the detonation over Hiroshima in 1945. A long list of similar incidents have been recorded since the Cuban missile crisis in 1962.[44] These “near misses” have demonstrated the various vulnerabilities in nuclear command structures, including control networks and human errors.[45]

The panel on risk during the third conference on the humanitarian impact of nuclear weapons, in Vienna, Austria, 8-9 December 2014 (Photo: Austrian Ministry of Foreign Affairs).

The panel on risk during the third conference on the humanitarian impact of nuclear weapons, in Vienna, Austria, 8-9 December 2014 (Photo: Austrian Ministry of Foreign Affairs).

Operational readiness

Several nuclear-armed states have adopted policies to use nuclear weapons first during a conventional conflict. Technical developments moreover enable the nuclear-armed states to shorten the time needed to employ these weapons. Many states have put their nuclear weapons on ever higher states of alert, thereby lowering the threshold for intentional use, and reducing the time available for detecting technical and human errors. (see text box 2).

All nine countries are preparing for the unthinkable. And in preparing for it they risk causing it—by miscalculation or accident, inadvertent escalation, or without authorization.[46]

Increasing geopolitical tension between Russia and the West in relation to Ukraine further increases the probability of use of nuclear weapons. Close encounters between Russian and Western military aircraft have spiked, and Russia is deploying missiles in Crimea capable of carrying nuclear warheads.[47]

Cyber risks

Another factor contributing to the increasing probability of nuclear weapons use is current developments of cyber weaponry. The spread of cyber weaponry increases the opportunities for state and non-state actors to exploit vulnerabilities in nuclear command structures. Nuclear assets are particularly vulnerable to cyber attacks, as these assets are complex and heavily computerized systems and remain as prime strategic target—as evidenced by the Stuxnet attack against the uranium enrichment facility at Natanz in Iran. Evidence shows that the number and scope of cyber weaponry and offensive cyber operations are growing and are likely to continue to grow in the future. There are, however, currently no internationally agreed standards explicitly regulating cyber warfare.[48]

Legal Aspects

Humanitarian considerations in international law regulating arms

Humanitarian considerations have been a motive behind restrictions on arms or means of warfare since the St. Petersburg Declaration of 1868, the first instrument that specifically regulated means of warfare in modern times. Originally aimed at protecting combatants, the discourse on humanitarian consequences that developed after World War II focused more on protection of civilians. Weapons of mass destruction as well as conventional weapons have been prohibited based on humanitarian concerns, including biological and chemical weapons, blinding laser weapons, anti-personnel mines and cluster munitions.[49]

The humanitarian discourse on nuclear weapons started as soon as they had been used in 1945. The two instances of use, in addition to use in the form of testing, is the backdrop for the humanitarian consequences discourse today. The debates leading up to the adoption of the Non-Proliferation Treaty (NPT) in 1968, the key legal instrument dealing specifically with nuclear weapons, were also based on humanitarian concerns as reflected in its preamble.[50]

In our view, the new evidence that has emerged in the last two years about the humanitarian impact of nuclear weapons casts further doubt on whether these weapons could ever be used in accordance with the rules of customary IHL.[55]

The conventions on biological weapons and chemical weapons can be seen as both non-proliferation and disarmament treaties, because they prohibit transfers and stockpiling and prescribe destruction of potential stocks. In addition, these two conventions constitute clear prohibitions on use. The NPT does not prohibit use, in spite of the fact that nuclear weapons pose an even graver humanitarian risk than other weapons of mass destruction. This may be seen as something of an international law paradox. [51]

International humanitarian law

The International Red Cross and Red Crescent Movement has concluded that “it is difficult to envisage how any use of nuclear weapons could be compatible with the requirements of international humanitarian law”.[52] The effects of nuclear weapons raise concerns under several IHL rules governing the conduct of hostilities:[53]

  • The rule of prohibition of indiscriminate attacks: The dispersion of heat, blast effect and radiation caused by a nuclear weapon detonation, will in most scenarios occur over wide areas. If used in or near a populated area, the blast will likely kill or injure very large numbers of civilians, and even if used against a military objective, it would be hard not to classify such an attack as striking military objectives and civilians and civilian objects without distinction. There is also a serious and foreseeable risk that the effects of a blast would not be limited in space and time, but continue long after the weapon was used.
  • The rule of proportionality in attack: The same effects also raise doubts that a nuclear weapon attack could respect the IHL rule of proportionality in attack, which requires that the foreseeable incidental impact on civilians and civilian objects must not be excessive in relation to the concrete and direct military advantage anticipated. This assessment should consider the immediate civilian deaths and injuries and damage to civilian objects that are expected to result from the explosion, foreseeable long-term effects of exposure to radiation, as well other foreseeable long-term repercussions, such as those stemming from damaged and destroyed water and electrical supply systems or health services.
  • The requirement to take precautions in attack: The devastating consequences of a nuclear weapon detonation raises doubts with regard to the requirement that constant care must be taken to spare the civilian population and to avoid or minimise civilian casualties and damage to civilian objects.
  • The prohibition of weapons of a nature to cause “unnecessary suffering”: The horrific short- and long-term illnesses, permanent disability and suffering caused by radiation exposure raise serious questions about the compatibility of nuclear weapons with the prohibition to cause unnecessary suffering.
  • Protection of the natural environment: Any decision to use nuclear weapons must take into account the potential impact on and damage to the environment. Even the use of a low-yield nuclear weapon far from civilian settlements would therefore raise questions of compatibility with IHL.[54]

International environmental law

There is no automatic suspension of international environmental treaties in case of conflict, but a presumption of continued operation, unless the treaty itself contains provisions to the contrary.

Of the environmental treaties that address this question specifically, some provide for enhanced protection during armed conflict (e.g. the World Heritage Convention), while other treaties allow for reduced environmental protection in exceptional circumstances (e.g. the Ramsar Convention on Wetlands). International environmental law does not explicitly regulate nuclear weapons, but it applies indirectly to different aspects of nuclear weapons. A number of international environmental treaties provide participation rights (right to access environmental information, to have a say in environmental decision-making and to access courts if these rights are not granted), which can be an important democratic tool for arms control. International environmental law can in some instances strengthen the content of specific human rights, as several rights have been interpreted as having an environmental component related to health. International environmental law applies beyond the protection of humans. A nuclear weapon detonation with limited impact on humans may thus still violate an environmental agreement. International environmental law also applies in peacetime and thus to the entire life cycle of nuclear weapons as pollutants from production to disposal. There are three important customary principles in international environmental law, relevant for the overall management of nuclear weapons: the principle of prevention and/or precaution, cooperation, and the requirement to conduct environmental impact assessments.[56]

International health regulations

International health regulations consist of three elements: the Constitution of the World Health Organization (WHO) from 2005, the International Health Regulations (IHR) of 2005 and the Convention on Tobacco Control of 2005. Due to the expansion of the definition of diseases made in the 2005 IHR, the health effects of a nuclear weapon detonation can be considered a disease.[57]

The international health regulations may therefore be applied in case of a nuclear weapon detonation as a framework for confirming and coordinating the public health response. For this to happen, a number of steps have to be taken. The country affected would formally notify the WHO, who in turn will notify the International Atomic Energy Agency (IAEA), The Emergency Committee of the IHR would be convened and provide its views on whether the event constitutes a “Public Health Event of International Concern” (PHEIC), after which the WHO Director-General would determine and communicate to States Parties whether the detonation would trigger the application of the regulations because of the ensuing ‘illness or medical condition’[58] affecting individuals. In this scenario the Director-General may issue temporary recommendations (authoritative, but non-binding) addressing a range of issues such as managing casualties, restrictions on food and drinking water, and distribution of potassium iodide.[59]


Unlike biological and chemical weapons, contemporary international law does not address the legality of nuclear weapons per se. Underneath the absence of a clear legal rule often lie profound moral ambiguities.[60]

Three major modes of ethical reasoning are relevant to nuclear weapons. First, consequentialist positions both for and against these weapons are built around their contested utility. One position insists that nuclear weapons should be allowed, insofar as they enhance international peace and security. The other position counters that nuclear weapons should be banned, because they endanger international peace and security. Although intuitive, consequentialism suffers from the ultimate verifiability of its respective positions. One can neither prove nor disprove the less desirable, counterfactual history against which each position asserts its moral superiority.[61]

Second, the just war theory combines consequentialist (such as proportionality) as well as non-consequentialist criteria (such as just cause) for evaluating the legitimacy of recourse to force. In the end, however, this theory concedes the possibility that responsible leaders of an organised, nuclear-armed political community faced with an existential peril may legitimately conclude that they have no choice but to threaten or use nuclear weapons.[62]

Third, deontologists examine the intrinsic moral status of an act, rather than the moral status of its consequences. Certain conduct remains wrongful per se, no matter how likely it may be to achieve its desired goals, or no matter how worthy such goals may be. Applied to nuclear weapons, the question is whether it is possible to develop a deontological position according to which the uniquely inhumane suffering that nuclear weapons inflict on their victims makes it inherently wrongful to use them. Torture was previously accepted, but is now considered inherently immoral and unacceptable as it robs humans of their humanity and reduces them to objects for others to use and take advantage of. If that is so, then the same may be said of nuclear weapons.[63]


[1]        Further information about the Conferences on the Humanitarian Impact of Nuclear Weapons, including expert presentations and statements by States and other stakeholders, can be found at: www.humimpact2013.no; http://mision.sre.gob.mx/oi/intranet/proyectos/index.php?id_proyecto=4&idioma=en; and http://www.bmeia.gv.at/en/european-foreign-policy/disarmament/weapons-of-mass-destruction/nuclear-weapons-and-nuclear-terrorism/vienna-conference-on-the-humanitarian-impact-of-nuclear-weapons/. Some presentations are not reflected in this summary, as ILPI were unable to access these presentations through the Nayarit conference website.

[2]       At the point of detonation temperatures are as hot as the surface of the sun (3,800 degrees Celcius). Mary Olson, War of Human Consequences: Health Consequences of the Use of Nuclear Weapons, Presentation at the Vienna Conference on the Humanitarian Impact of Nuclear Weapons, 8 December 2014.

[3]       Ibid.

[4]       All figures are approximate. SIPRI, World Nuclear Forces, 2014.

[5]       Andy Haines, Nuclear Weapons: Catastrophic Impacts on Health, Presentation at the Oslo Conference on the Humanitarian Impact of Nuclear Weapons, 4 March 2013.

[6]       Elin Enger and Thomas Vik estimate that within the first 24 hours, more than 100,000 people would be killed or injuried should a 20-kiloton warhead be detonated in Oslo, Norway. Scenario of a Nuclear Detonation, Presentation prepared by the Norwegian Defense Research Establishment (FFI) and Norwegian People’s Aid (NPA), 4 March 2013. See also Mary Olson, 2014.

[7]       Scenario with a one-megaton warhead detonated 2000 metres above ground. Elin Enger and Thomas Vik, 2013.

[8]       Andy Haines, 2013.

[9]       Mary Olson, 2014.

[10]      Ibid.

[11]       Andy Haines, 2013 and Ibid.

[12]      Elin Enger and Thomas Vik, 2013.

[13]      ICRC Resource Centre, quoted by Mary Olson, 2014.

[14]      Mary Olson, 2014.

[15]      U.S. National Academy of Sciences BEIR VII Phase II study, quoted in Mary Olson, 2014.

[16]      These categories are based on research conducted by the Institute of Radiation Medicine and Ecology (IRME), reproduced in Roman Vakulchuk and Kristian Gjerde with Tatiana Belikhina and Kazbek Apsalikov, Semipalatinsk nuclear testing: the humanitarian consequences, NUPI Report: no. 1, 2014, p. 9, prepared for the Nayarit Conference on the Humanitarian Impact of Nuclear Weapons, 13-14 February 2014. The NUPI study underlines that there is disagreement about the level of radiation exposure and the health impacts, and that further studies are being conducted in this regard.

[17]      Sumihisa Honda, Psychological Damage Study for Survivors after a Half Century (1995) by WHO General Health Questionnaire, cited by Masao Tomonaga, The Lifelong Health Effects of Atomic Bombs by Immediate DNA Damage, Presentation at the Oslo Conference on the Humanitarian Impact of Nuclear Weapons, 4 March 2013.

[18]      Roman Vakulchuk et al, 2014.

[19]      Neil Buhne, Presentation at the Oslo Conference on the Humanitarian Impact of Nuclear Weapons, March 4, 2013.

[20]     Ira Helfand, The Wider Impact: Long-term Effects on Health, Environment and Development, Presentation at the Oslo Conference on the Humanitarian Impact of Nuclear Weapons, 4 March 2013.

[21]      The accident at the Chernobyl nuclear power plant in April 1986 caused widespread radioactive contamination in large areas of Ukraine, Belarus, the Russian Federation, as well as parts of Western Europe. Chernobyl Forum, Chernobyl’s Legacy: Health, Environmental and Socio-economic Impacts, 2006.

[22]      Neil Buhne, 2013.

[23]      Valerie Amos, Opening Address at the Oslo Conference on the Humanitarian Impact of Nuclear Weapons, 4 March 2013. Delivered by Rashid Khalikov.

[24]      Neil Buhne, 2013.

[25]      Ibid.

[26]      Ibid.

[27]      Michael J. Mills, Global Famine after a Regional Nuclear War: Overview of Recent Research, Presentation at the Vienna Conference on the Humanitarian Impact of Nuclear Weapons, December 8, 2014.

[28]      Ibid.

[29]      Ibid.

[30]     Ibid.

[31]      Gregor Malich, Challenges in Responding to the Use of Nuclear Weapons, Presentation at the Oslo Conference on the Humanitarian Impact of Nuclear Weapons, March 5, 2013.

[32]      Rudolph Muller, Responding to the Humanitarian Consequences of Nuclear Weapons Use in Populated Areas, Presentation at the Vienna Conference on the Humanitarian Impact of Nuclear Weapons, December 8, 2014.

[33]      Rashid Khalikov, Humanitarian Preparedness and Response, Presentation at the Oslo Conference on the Humanitarian Impact of Nuclear Weapons, March 5, 2013.

[34]      Gregor Malich, 2013.

[35]      Rashid Khalikov, 2013.

[36]      Ibid.

[37]      Micah D. Lowenthal, Preventing and Preparing for a Nuclear Explosion, Presentation at the Vienna Conference on the Humanitarian Impact of Nuclear Weapons, December 8, 2014.

[38]      Ole Harbitz, Emergency Preparedness and Response in the Event of a Nuclear Detonation—The Case of Norway, Presentation at the Oslo Conference on the Humanitarian Impact of Nuclear Weapons, March 5, 2013.

[39]      Micah D. Lowenthal, 2014.

[40]     Adriana Baciu, Emergency Preparedness and Response in the Event of a Nuclear Detonation—The Case of Romania, Presentation at the Oslo Conference on the Humanitarian Impact of Nuclear Weapons, March 5, 2013.

[41]      Patricia Lewis, Heather Williams, Benoît Pelopidas and Sasan Aghlani, Too Close for Comfort: Cases of Near Nuclear Use and Options for Policy, Chatham House (2014). Preliminary conclusions of report presented in Nayarit.

[42]      Seth Baum, Executive Director, Global Catastrophic Risk Institute, at the Vienna Conference on the Humanitarian Impact of Nuclear Weapons.

[43]      Seth Baum, What Is the Risk of Nuclear War?, Presentation in Vienna, 8 December 2014.

[44]      Patricia Lewis et al, 2014.

[45]      Eric Schlosser, The Most Dangerous Machines, Presentation in Vienna,
8 December 2014.

[46]      Bruce G. Blair, Lowering the Nuclear Threshold: The Dangerous Evolution of World Nuclear Arsenals toward Far-Flung Dispersal, Hair-Trigger Launch Readiness, and First Use Doctrines, Presentation in Vienna, 8 December 2014.

[47]      Ibid.

[48]      Camille M. Francois, Cyber risks in securing nuclear weapons from unauthorized or inadvertent use, Presentation in Vienna, 8 December 2014.

[49]      Gro Nystuen ,The Humanitarian Origins of International Law Regulating Arms, Presentation at the Vienna Conference on the Humanitarian Impact of Nuclear Weapons, 8 December 2014.

[50]     Ibid.

[51]      Ibid.

[52]      Resolution CD/11/4.1, Working towards the elimination of nuclear weapons, adopted by the Council of Delegates of the International Red Cross and Red Crescent Movement, 26 November 2011.

[53]      Helen Durham, The Use of Nuclear Weapons and International Humanitarian Law, Presentation at the Vienna Conference on the Humanitarian Impact of Nuclear Weapons, December 8, 2014.

[54]      Ibid.

[55]      Ibid.

[56]      Jorge Vinuales, Nuclear Weapons and International Environmental Law, Presentation at the Vienna Conference on the Humanitarian Impact of Nuclear Weapons, December 8, 2014.

[57]      Steven A. Solomon, Nuclear Weapons and International Health Law, Presentation at the Vienna Conference on the Humanitarian Impact of Nuclear Weapons, December 8, 2014.

[58]      World Health Organisation, IHR 2005.

[59]      Steven A. Solomon, 2014.

[60]     Nobuo Hayashi, The Fundamental Ethical and Moral Principles on which International Legal Regulations of Nuclear Weapons and Based, Presentation at the Vienna Conference on the Humanitarian Impact of Nuclear Weapons, December 8, 2014.

[61]      Ibid.

[62]      Ibid.

[63]      Ibid.