The United States is the only nation to have used atomic weapons for the mass slaughter of civilians. What happened in Japan was not necessary to defeat the enemy but to deter an ally (as the Soviet Union was at that time) from promoting a more progressive post-war settlement in east Asia, and to proclaim the new Pax Americana.

On 24 January 1946, while world opinion was still shaken by the U.S. war crimes in Hiroshima and Nagasaki, the first resolution of the United Nations General Assembly, then representing 51 states, called unanimously for the complete elimination of nuclear weapons and set up a commission to handle the issue.1

Alongside China, the USSR had suffered most from fascism and contributed most to its defeat but now had to look to its own defence. The world’s first defensive nuclear weapon was tested on 29 August 1949, and since then its Soviet, Russian, Chinese and North Korean successors have dissuaded the U.S. from undertaking a first (or ‘pre-emptive’) strike against enemy targets. In the meantime, and especially since the defeat of Socialism in the USSR and eastern Europe, the spread, hoarding and destructive capacity of all such weapons, and the military contexts in which they might be used by accident or design, have dangerously increased.

Since it is inconceivable that the US top brass does not appreciate the “mutually assured destruction” (MAD) of a full-scale nuclear exchange, their ‘first strike’ policy, even if only covert, aims to weaken the enemy’s economy by forcing it to overspend on defence. This was the successful logic of President Reagan’s “Star Wars” strategy. US first strike policy claims to respond to the same policy of the other side.2

Since the 1980s, the existential threat of nuclear war has been joined by another: the comparably alarming, but more easily measured, threat of global warming. Although their causes are different, if either threat was realised it could trigger the other and intensify yet further its impact on the most vulnerable, the whole of humanity or even life itself.

The best-known risk in which a nuclear exchange triggers environmental collapse is the “nuclear winter,” first discussed in US military circles in the early 1980s, around the same time that climate change itself was becoming a major concern. (3) Even only a few nuclear detonations, if big enough, could scatter sufficient debris in the atmosphere to blot out the sun and interrupt photosynthesis, on which human food-chains depend, causing in turn a “nuclear famine.” The bigger the bombs or the more (or more prolonged) the explosions, the more likely they would leave the world lifeless for the first time in 3.7 billion years.

In a second scenario, climate crisis precipitates war, potentially nuclear. Climate scientists and demographers warn that international conflict, potentially escalating into nuclear war, grows more likely as the Earth heats up, driving increasingly desperate competition for essentials like water, food and relief from extreme temperature and/or rising sea levels. In these respects, peoples of the global South and the poorer sections of all nations are already disadvantaged. For them, further global warming only makes a bad deal worse, but global climate and supply-chains mean not even the currently privileged can escape the looming catastrophe (though some billionaires may try to migrate to Mars).

Furthermore, it’s not hard to imagine in this second scenario a nuclear conflict serious enough to trigger the first.

The catastrophic scenarios referred to above are plainly, but not totally, different from everyday situations which emergency service personnel are trained to tackle. Larger-scale emergencies, like famines, hurricanes, earthquakes, floods, pandemics, fires, road, rail or air crashes, sinking ships, collapsed mines, crushed crowds, and similar events, demand pooling responses beyond those locally available, and sometimes at international scale. And no-one makes a fuss that they are funded from general taxation.

The impact of global warming is already being felt in famines, the spread of disease, emergence of new pathogens, and in extreme weather patterns, which still cost lives although only a fraction of what we or our successors can expect from full-scale climate collapse.

Such increasingly familiar events demand an immediate life-saving response but since they are also alarm signals of worse to come, the response needs to be not just by “firefighting” in the present or “capacity building” against similar or more severe risks in the future, but above all by reducing them. So far, so logical; but unless funds are available to manage both relatively minor (even if increasingly serious) short-term risks and, in the longer-term, risks that have been hitherto unthinkable, then planning for the long-term will never be taken seriously.

In the past, socialist countries for most of their existence popularised, at least, five-year plans and in the capitalist West, during its most stable period after the Second World War, some major corporations followed suit, though in a commensurately more limited way. More recently, China’s five year plans explicitly anticipate the interests of future generations. In short, where current conditions allow, socialist planning takes posterity seriously, but to slay the dragons of nuclear war and climate collapse in the time available, we don’t have the luxury of socialist planning cycles.

Co-ordinated global action (including potential contributions from enlightened capitalist interests) to reduce and finally remove the existential threats of nuclear war and climate collapse can’t happen too soon. But well short of such worst-case scenarios are, nevertheless, kinds of activity which, although rarely discussed in such terms, could contribute much to overcoming them. To put this more strongly, it is hard to imagine how winning the war against such catastrophes could happen at all without smaller, contributory victories along the way. One way to do that could be to campaign both for peace and for meeting internationally agreed carbon emission targets.

From October 2023 until January 2025 probably most of the carbon footprint of Israel’s still-continuing genocide in Gaza was the airfreighting of military support from the US and Israel’s own delivery systems and exploded ordnance which, “exceeded the annual planet-warming emissions of a hundred individual countries”. Although Israel is a nuclear power heavily dependent on another (the US), it’s worth noting that this military shortening of odds against the Earth’s longer-term interests happens without deploying nuclear weapons.

Global defence spending – for imperialist powers, “defence” often covers aggression as well – includes the cost of military bases, the vast majority American, as well as of more conspicuous budget lines such as open hostilities, and increasingly of expensive, high emission-generating AI infrastructure. In a recent issue of the eminent science journal Nature, Chinese researchers reveal how such expenditure seriously obstructs efforts to meet IPCC (Intergovernmental Panel on Climate Change) mitigation targets. Further damage is also done by the militaries of, and conflicts between, non-imperialist nations: climate is indifferent to the excuses of those who affect it.

In strictly scientific terms, nuclear war and/or climate collapse are real threats, yet the means and understanding necessary to avert them are still available. The scientific justification of such concerns is widely known and needs no repetition here. However, if past foolishness can’t now be undone, present foolishness divides climate deniers from those who accept the science, and sets the fearful, panicked and unconvinced at each other’s throats. “Divided we Fall” is another way of saying we are not yet united by what we agree on. That is why it matters to organise for social well-being – sustainable jobs, health, housing, education, transport, genuine security – and against the dangerous, wasteful and unsustainable drive to war.

The working class and its potential allies, despite all current divisions, share far more in their everyday lives than divides them in their assessments of the chances of nuclear or climate disaster. One of the great principles of trade union organisation, which is also the experience of people drawn into collective activity at community level, in political parties or in campaigning on almost anything, is of course “Unity is Strength” - the classic alternative to “Divided we Fall.” Not everyone whose support is needed in the struggle for a sustainable planet can be expected to rally to the Labour Movement’s best-known principle, nor will the principle alone be enough for those who can.

But the numbers of people with experience of collective struggle have been declining for decades with de-industrialisation, fragmentation of production and service employment, digitising of the social sphere and anti-trade union legislation; and this was only made worse by the pandemic. People have not only been denied that more collective experience but pushed increasingly into social and therefore political isolation.

For many, especially younger people, social media certainly offers alternative views – an outstanding example is its unrivalled coverage of the Gaza genocide when Israel excluded even complicit mainstream media from on-the-spot reporting.

The UK’s expression of solidarity with Palestine since October 2023 is most remarkable not just in scale but in its consistency, which could show that if the issue resonates with them and if their collective action has an impact, then even broader sections of people can begin to overcome the isolation and frustration encouraged by decades of stale capitalism to surge united towards a viable future.

• In 2011, a highly-respected specialist in the field of assessing such risks, Prof. Martin E. Hellman, wrote, “[…] a child born today may well have less-than-even odds of living out his or her natural life without experiencing the destruction of civilization in a nuclear war.”
• In 2018, environmental scientist Jem Bendell, “consider[ed] it inevitable [from evidence then available] and already occurring, that climate change will lead to the collapse of our societies and, consequently, the end of our own lives.”3
• On 28 January 2025, The Bulletin of Atomic Scientists recalibrated its Doomsday Clock from 90 to 89 seconds short of its fateful midnight, the closest since its inception in 1947, when it was set at seven minutes to midnight.4

As far as can be seen, none of these authorities have direct, personal experience of organising or participating in broad-based campaigns involving people from different backgrounds and experiences. This might not excuse their pessimism but could help explain it.