The Coming Storm, the new book by Yale historian Odd Arne Westad on great powers and the prospects for world war, is attracting considerable attention. Westad’s basic argument is that today’s pattern of great-power relations bears an uncomfortable resemblance to the years preceding the First World War. The point is not that history repeats itself mechanically, but that the convergence of strategic rivalry, nationalist sentiment, and mutual insecurity has recreated conditions that should alarm us. This toxic brew led to catastrophic war once and could do so again.
However, the book’s argument rests on a premise so unexamined it has become invisible: that the climatic conditions under which great powers operate will remain essentially unchanged. Westad does not mention, let alone analyse, how the changing climate might affect strategic calculation and the relative power of major states. He writes as if three decades of scientific research—and the already-realised predictions of that research—can be treated as an aside, a matter for specialists rather than strategists. In this view, the irreversible disruption of the functioning of the Earth System is not worth mentioning, even in a footnote. For those attentive to the scientists’ warnings, on the other hand, climate change is transforming the very conditions under which geopolitical power is exercised, so its omission is not a minor oversight but a structural flaw.
A quick reminder
The scientific consensus, as expressed in the IPCC Sixth Assessment Report (2023) and reinforced by subsequent research, is that even under optimistic emissions scenarios the world is locked into at least 1.5°C of warming above pre-industrial levels within the next decade or so, with current policies tracking closer to 2.5–3°C in the second half of the century. Crucially, the relationship between warming and extreme weather is non-linear, so that impacts intensify disproportionately with each fraction of a degree.
The result is not a smooth gradient of worsening conditions but an accelerating incidence of severe and compounding disasters—floods devastating agricultural regions, storm surges inundating coastal cities, heatwaves killing multitudes, and tipping points triggering ice sheet collapse or Amazon dieback with dire global effects. Several of these tipping points may be crossed at temperature increases as low as 1.5–2°C, producing cascading disruptions to food and water systems, power infrastructure, and state capacity.
This shifting terrain of great-power rivalry Westad disregards. His classical realist framework is built around states, power, prestige, miscalculation, and alliance entanglements. Climate change does not fit that framework. It is not an actor, it arrives from outside the system of sovereign states, it does not respect borders, and it does not map neatly onto the bilateral rivalries that realist historians analyse. The omission is not a matter of analytical preference. Climate change does not merely add pressure to the system Westad describes; it is transforming the operating environment of great-power competition in ways that challenge the most basic assumptions of his framework.
The hidden assumption of classical realism
Classical realism assumes that while state actors form and dissolve alliances, build navies, and jockey to increase their relative power, the physical platform of the strategic environment remains stable. In Westad’s early twentieth century world, territory is fixed, the climate is a background condition, and states are coherent units. The realist tradition’s hidden assumption of climatic stability is the characteristic feature of the Holocene epoch stretching back 10,000 years. That epoch has now been superseded by the Anthropocene, a rupture in the functioning of the Earth system, a definitive break in planetary history that centres on climate change but goes well beyond it.
What climate change introduces is something realist theory has no category for—hard, non-negotiable physical constraints that degrade the internal foundations of competing powers at differing rates. The language of ‘threat multiplier’—which the U.S. Department of Defense has used since 2014—understates what is actually at stake. What we are beginning to see is a process of differential climate attrition. The great powers are being destabilised by the same background process but at unequal rates and with unequal consequences for internal stability and regime legitimacy. This asymmetry is itself strategically destabilising in ways that have no clear historical precedent.
Westad’s error is not that he ignores one more variable. It is that he assumes the strategic environment itself remains stable while only the actors within it change. In the Anthropocene, the assumption that we continue to operate within the planet’s ‘safe operating space’ is no longer true.
Escalating disaster emergencies
Among the major powers, China is by far the most exposed to severe and compounding climate impacts. The North China Plain, home to some 400 million people and the nation’s agricultural and industrial heartland, is already at the edge of ‘wet-bulb temperature’ thresholds, where heat and humidity combine to make outdoor labour physiologically impossible. Across the country, the brutal summer of 2023 saw debilitating droughts alongside floods and heatwaves. Temperature records were obliterated and ‘heatwave exposure days’ were three times higher than the historical average. A year earlier, one leading climate scientist described ‘the most severe heat event in global recorded history,’ adding, ‘There is nothing in world climatic history which is even minimally comparable to what is happening in China.’
The Yellow River basin faces severe long-term water stress. Coastal megacities—Shanghai, Tianjin, Shenzhen—face compounding risks from sea-level rise and intensifying typhoons. Flows into the Yangtze River, on which China depends heavily for hydropower and irrigation, are increasingly variable and subject to extremes. And China’s food security strategy depends heavily on imports from sub-Saharan Africa and Southeast Asia, regions themselves acutely threatened. Climate-related extreme weather has become a major driver of internal displacement and migration in China in recent years.
The United States also faces severe disruptions. Like China it is large and climatically diverse, but it is considerably wealthier per capita and may have substantially greater adaptive capacity. The American South is prone to more severe hurricanes. Coastal Florida and Louisiana are particularly exposed but a hurricane’s path can now reach as far north as North Carolina and Tennessee. The Southwest faces a structural water crisis. California and the Pacific Northwest experience catastrophic wildfires. Over the five years to 2024, the U.S. averaged around 23 billion-dollar weather disasters per year, more than double the long-run historical average. Insurers are withdrawing from some regions entirely. Migration pressure at U.S. borders attracts attention; what is rarely acknowledged is the mass internal migration to the north and away from the coasts of the nation. (I discuss this in a forthcoming book.)
Among other significant powers, India is in some respects more severely exposed than China, facing heat-stress mortality, monsoon volatility, coastal flooding, and Himalayan glacier retreat that threatens the water flows of the Indus and Ganges systems. Nuclear-armed India and Pakistan are already competing fiercely over Indus water, and Bangladesh could produce tens of millions of climate refugees within decades, most moving toward India. Europe will need to manage an increasingly unliveable south and climate migration both internal and from beyond its borders, with attendant political fractures. Russia hopes to benefit from warming through longer growing seasons and Arctic access—until the costs outweigh any benefits. Brazil faces potential collapse of the Amazon into degraded savanna, with severe consequences for agricultural productivity, hydropower and social stability.
With the globe already nearly 1.5°C warmer than pre-industrial levels, and given the non-linear intensification of extremes with each fraction of warming, it’s been estimated that the generation born in the 2020s will experience up to seven times more extreme heatwaves than their grandparents.
The geopolitics of resilience
The geopolitical significance of this picture lies both in the aggregate scale of disruption and in its differential distribution—what we might call geophysical asymmetry. Westad’s 1914 analogy assumes rough comparability among the great powers in terms of what they stand to lose from instability and conflict. Climate change cuts across his cast of characters in a way that disrupts this symmetry fundamentally.
For China, the consequences extend beyond economic cost. The Chinese Communist Party derives its domestic legitimacy and international reputation from its ability to maintain social order and deliver economic security. Climate adaptation is therefore not merely environmental policy but a core regime security imperative—a point Beijing’s National Climate Change Adaptation Strategy 2035, launched in 2022, makes explicit. More extreme weather events will force repeated diversion of attention and resources inward to disaster response, population displacement, agricultural disruption, and reconstruction. This does not necessarily make war less likely, but it changes the character of strategic competition. States becoming simultaneously more inward-looking and more anxious about external threats to essential resource supplies is a combination that Westad’s framework is not equipped to handle.
Differential exposure also forces a reconsideration of what constitutes power in the first place. Westad assumes that the currency of international power consists principally of military capability, economic strength, alliance structures, and strategic geography. Under conditions of escalating climate disruption, states must have the capacity to maintain political order during repeated disasters. They must protect food, water, and infrastructure systems, sustain state legitimacy under environmental stress, and invest systematically in resilience. These constitute a new and increasingly consequential dimension of national power. This geopolitics of resilience does not map onto classical realist categories.
On the China-US rivalry that lies at the heart of Westad’s concerns, the outcome will depend not only on who accumulates more military power and technological leadership but on who more effectively builds resilience to climate extremes. China has been implementing a massive investment programme in climate-adaptive infrastructure—enormous projects to divert water from the south to the north, sponge cities for flood protection, and thousands of kilometres of seawalls. The United States lags behind, afflicted by institutional fragmentation and a political culture that has made emergency preparedness a partisan question. In the resilience stakes of a post-Holocene world, the hierarchy of power looks quite different from the military-industrial calculus that dominates Westad’s analysis.
Domestic disorder and external rivalry
Classical realism assumes that domestic politics happens inside states while geopolitics happens between them. Climate change is dissolving this distinction. Disasters poorly handled undermine state legitimacy, and responses to internal emergencies shape external behaviour when food security becomes foreign policy, when migration becomes geopolitics, and when solar geoengineering is a strategic threat. Future geopolitics will increasingly be the external projection of domestic climate stress.
In other words, the changing climate is domesticating geopolitics. Great-power competition will increasingly originate not in expansionist ambition but in attempts by states to preserve domestic stability and state legitimacy under environmental stress. The Syrian civil war, which fed into European political destabilisation through migration, was preceded by the worst drought in Syria’s recorded history. Climate-driven instability in the Sahel, Central Asia, and South and Southeast Asia does not merely instigate humanitarian crises; it generates the peripheral frictions and entanglements that can draw great powers into confrontation.
The erosion of the distinction between domestic and international order extends to the physical boundaries of states. Classical realism and Westad’s entire historical framework rely on the ontological stability of the state; borders are fixed lines across which armies move. As the twenty-first century advances, the container of the state itself becomes porous. At the extreme end, some nations in the Pacific may disappear completely, leaving citizens of phantom states. Bangladesh faces massive coastal losses and refugee outflows that are already reshaping regional politics. New York, Shanghai, Jakarta and Bangkok face serious inundation risks.
The world begins to resemble less the Europe of 1914 than a system of states struggling to maintain political order and economic continuity amid mounting environmental disruption. Under these conditions, adaptive sovereignty—the demonstrated capacity to protect and sustain a population through escalating environmental shocks—begins to displace military dominance as the operative measure of viable statehood. After all, the historical record shows that states and civilisations can collapse when the climate shifts.
Unsafe analogies
Given these dynamics, Westad’s analogies with 1914 become progressively less illuminating. His historical comparisons assume a continuity with previous eras of great-power politics in which the physical platform of the strategic environment remained stable and predictable. These are the conditions of the Holocene epoch, one now disappearing in the rearview mirror.
Westad’s parallel is misleading in a further respect. One element that enabled the outbreak of the First World War was the belief among the great powers and their peoples that a short war was manageable (‘We’ll be home by Christmas’) and that the pre-war social and economic order would resume intact. Climate change introduces a background process that is already degrading the material foundations of state capacity for several key players, regardless of whether war occurs. The great powers of 1914 did not face a condition that was simultaneously weakening them all, but asymmetrically, one that required their cooperation to address. Instead of a cooperative resolution of the global problem, China and the United States are pursuing diverging responses to its consequences—spend heavily on resilience and do nothing.
Westad worries about a replay of 1914. The deeper risk is something without historical precedent, that is, great powers whose internal foundations are being eroded at asymmetric rates by a process none of them can arrest individually. A rival may be simultaneously more desperate and more dangerous than any actor in the classical realist canon. A Chinese state under compound climate stress, led by a party that has staked its legitimacy on uninterrupted growth and the protection of its population, operating in a world where the still-dominant power is comparatively less stressed, may be a more volatile actor than pre-1914 Germany. The most dangerous power in the twenty-first century will not necessarily be the strongest, but the most desperate.
China’s investments in African agriculture and water infrastructure, its efforts to control Himalayan river systems, and its Arctic strategy are not merely commercial plays; they are climate-adaptive strategies with direct security implications. Westad’s pre-1914 great powers competed over colonies, trade routes, and prestige. Climate change adds water, arable land, critical minerals, and Arctic access as objects of great-power competition in forms that have no analogue in 1914.
The resilience state
Perhaps the deepest analytical absence in Westad’s framework is this: climate change is creating a situation where the great powers he identifies as most at risk from each other have also been the powers most in need of each other’s cooperation. Britain and Germany before 1914 did not need each other to prevent a planetary process displacing their populations regardless of how their rivalry was resolved. China and the United States do. It is a structural irony that classical realism, focused as it is on interstate competition, cannot easily accommodate.
Rather than a 1914-style confrontation, the world may be heading toward a struggle between powers whose internal stability and adaptive capacity are being eroded at different rates by a background process none of them can alone arrest. The end of the Holocene is converting military powers into resilience powers and turning domestic climate emergencies into drivers of international politics. The shift from the balance of power to the balance of survivability is an analytical move that the realist framework cannot make and the reason why Westad’s account is, for all its learning, rests on foundations that no longer pertain.
Today, when reading a book on geopolitics, climate change should not be something we have to search for in the index; if climate science is to be taken seriously, the disruption of Earth System functioning should be woven through the text. It is the condition under which all future geopolitics unfolds.
Clive Hamilton is the author of Negotiating the End of the World: Kant, Schmitt, and the Global Climate Struggle, published in June 2026 by Polity Press.