Most people prefer not to think about the worst that can happen. Even those who talk of World War Three experience a mental block about imagining the aftermath.

But decisions taken over nuclear posture and potentially the use of nuclear weapons must fully account for the consequences. Ignorance weakens deterrence and exacerbates risk. We don’t plan national resilience so well. We reduce the chances of national survival, or at least human civilisation’s survival. We make recovery from catastrophe that much harder.

Scientists have been analysing what the physical consequences of an all-out nuclear war would be. Would soot in the atmosphere trigger a nuclear winter? What effects would a nuclear electro-magnetic pulse have on IT systems? Could nuclear survivors grow enough food to live? They have even tried to estimate the number of fatalities arising from different scales of nuclear war, concluding that fatalities from famine and climatic effects would likely be far greater than those from direct effects.

But if the concern is around deterrence, resilience, the survival of civilisation, and recovery, something is missing from their analysis. The cascading damage to human relations – social, economic, and political – could be just as destructive as the physical consequences. These social, economic, and political factors have barely begun to feature in the research, and (with some exceptions) there is little planning within governments for the aftermath of a nuclear exchange.

We can guess that in the face of extreme hardship, there would be heroism, compassion, inventiveness, and efforts at recovery. We can hope that there might be statesmanship and collaboration. But there would also be anarchy and chaos, driven by fear, misinformation, and tribalism.

Our complex world is now more vulnerable than it was when nuclear weapons were used on Hiroshima and Nagasaki in 1945. The trains were running into Hiroshima within three days of the blast because nuclear radiation was not understood. Today, the fear of radiation is universal. It is easy to imagine that tens of millions would flee. It is harder to imagine borders being opened to them unless those borders were overwhelmed. Is Africa ready for the European migrant flood? Or Mexico for the American one?

Moreover, in 1945 only two cities were hit – with bombs relatively small by today’s standards. Each of the 40 or so UK nuclear warheads aboard a Trident submarine is more powerful by a factor of about six. There are thousands of weapons available to Russia and the US and hundreds to the other seven nuclear-armed states. The main nodes of civilisation in warring states – transport, shipping, energy, communications – might be hit multiple times.

Our highly interdependent modern systems of organisation, finance, and international trade mean that there are many more single points of failure. This risks triggering cascading disruptions through the value chains of the world’s economies.

Nuclear war would occur in the northern hemisphere. At least 70% of global trade is in or with the North. Some 60% of the world’s servers are in the USA. The Euro-Atlantic and China account for over 50% of the world’s GDP. If all this were eliminated or massively disrupted, southern hemisphere societies might also implode.

Even the leaderships within countries not immediately affected would experience severe challenges to governance – potentially without TV, radio, internet, social media, finances or even functioning economies.  Evidence is mixed on how humans react when in mortal crisis. But it seems likely that those local communities that still retained some resources and capabilities would prioritise their own survival in possibly self-defeating protectionism.

The nature, scale, and longevity of climatic, radiation and electromagnetic pulse effects from a nuclear Armageddon would be harder to forecast than a pandemic or rising sea levels.  And compared to climate change or a bio disaster its effects could be quite sudden and simultaneous, leaving little or no time for most of the international community to brace for the shock, let alone to adapt. Those areas unaffected directly by blast and radiation would need rapidly to anticipate reduced sunlight and cascading socio-economic impacts and take emergency action.

In summary, no communities, no corner of the planet would be immune. The second and third-order human effects could be massive. This includes vast population displacements, sudden disruptions to ordinary ways of life in countries far removed from the conflict, extreme dislocations of economies, acute tensions between affected nations, and significant loss of leadership and coordination capacity. Human civilisation might continue. But it could be a pale shadow, constrained, localised, and diminished.

So, what to do?

Of course, avoiding nuclear catastrophe in the first place is the best answer. However, a better understanding of the full consequences of failure would enable us to factor the risk into our strategies going forward. The US National Academies of Sciences study on potential environmental effects and socio-economic consequences from nuclear war mandated by Congress and expected to report in the next year or two may assist. Intergovernmental agencies with global responsibilities are beginning to turn their attention to these risks. But there is a compelling case for at least a first-order-of-magnitude global study of the impacts on the basic human needs of water, food, shelter, health, security, community, and governance, bringing together subject matter experts and government policy experts to identify the top priorities for response.

Given better understanding, plans, preparations, mitigations, and means of recovery could follow. Some degree of emergency preparation could be undertaken—not only to establish response infrastructure (such as seed banks) but also to prepare resilience coordination and governance mechanisms.

Practical action, in turn, would help ensure that strategists, political leaders, and supporting officials are familiar with the consequences of failure in nuclear deterrence. That should help to reduce that risk. It might also better motivate us to collaborate in the search for solutions. This is a particular responsibility for governments engaged in supporting nuclear deterrence, but it is a responsibility for all governments with publics that would suffer the human effects. In other words, all governments.

The opinions articulated above represent the views of the author(s) and do not necessarily reflect the position of the European Leadership Network or any of its members. The ELN’s aim is to encourage debates that will help develop Europe’s capacity to address the pressing foreign, defence, and security policy challenges of our time.

Image: Composite, from Wikimedia Commons and Pexels.