Revisionism reconsidered: grand strategy in a post-imperial age

The desire to revise territorial boundaries through war, coercion, diplomacy, or some combination of the three, was a regular, if not normal, part of international political life before the middle of the 20th century. Three interrelated factors chilled revisionism in the three quarters of a century that followed.

First, the approval and adoption of the United Nations Charter banned the use or threat of force to revise territorial borders. Revisionism was, thereafter, illegal as a matter of international law.

Second, an intense geopolitical and ideological competition emerged from the two global superpowers, the Soviet Union and the United States. Each battled for formal or informal political control and influence of territories around the world, crafting alliances, interdependent institutions, and economic zones and security arrangements that solidified boundaries. In this bipolar struggle, any shift in political allegiance, to say nothing of territory, was fiercely contested.

Third, the nuclear and thermonuclear revolution massively increased the stakes in any effort to revise borders. The Bomb was a blunt instrument of power, whose greatest salience rested in its ability to deter invasion and conquest through the promise of unimaginable retaliation.

These three powerful, intertwined, often reinforcing factors obviously did not eliminate war, coercion, violence, or revisionism after 1945: there were wars in East and South Asia, the Middle East, Africa and elsewhere to revise boundaries. And one could argue that prohibiting the revision of boundaries – a regular and even occasionally stabilising occurrence in the past – may have funnelled political, ideological, geographical and ethno-religious disputes and energies into bloody civil, proxy, intrastate wars. Overall, however, international relations saw a marked decrease in conflict to revise boundaries.

To many, recent renewed violence in the Middle East, simmering conflict in South Asia, the Korean peninsula and parts of Africa, China’s increased aggressiveness and, especially, Russia’s conquest of Crimea in 2014 and invasion of Ukraine in 2022 all reflect a weakening of the prohibition on revisionism. All three of the postwar forces that chilled revisionism, some suggest, have weakened. The Cold War is long over and the unipolarity that followed has faded if not disappeared. Not only is the waning hegemon, the United States, unable to enforce the stricture against revisionism; the second Trump administration appears revisionist itself, with explicit or implied threats to acquire, through coercion or force, Greenland, the Panama Canal, even Canada.

Furthermore, the credibility and effectiveness of the United Nations has declined in this emerging multipolar world. Finally, some have questioned whether nuclear deterrence, and the previously unbreakable shield that appeared to prevent states from penetrating the territorial integrity of nuclear armed states, has lessened. Iran’s attacks on nuclear-armed Israel, Ukraine’s assaults on nuclear superpower Russia, and India’s May 2025 airstrikes deep within Pakistan appear to have weakened previous taboos. Extended nuclear deterrence, always exposed to credibility concerns, seems increasingly vulnerable because of America’s erratic grand strategies.

Has revisionism returned to world politics? To answer that question, it is important to ask what kind of revisionism we are concerned with. All three of the mid-20th century inhibitions – the UN, the Cold War and the nuclear/thermonuclear revolution – unfolded, were structured, and interpreted with the recent past and a particularly vicious form of revisionism in mind. What was that history?

Starting in the late-19th century, intensifying with the First World War, and culminating in the horrors of the Second World War, international relations were traumatised by the unprecedented horror of fully mobilised, ideologically driven, industrialised wars of empire and conquest, leading not only to tens of millions of combatant deaths, but scores of millions of civilian casualties resulting from pogroms and genocides, revolutions and civil wars, and war-driven famine and disease. This extreme form of revisionism was driven by specific historical conditions and circumstances, emanating from a world much different than our current one.

This does not mean revisionism has disappeared, nor would eliminating it entirely be a realistic, easily achieved goal. World politics is never static, and there are many causes of war: Thucydides reminds us that it is driven by fear, honour or interest, in that order. Revisionism is often caused by a desire to restore honour that is perceived to have been lost. There are forms of revisionism that fall far below the kind that scarred the world in the first half of the 20th century, however. Irredentism, or the desire by a state to recover a territory that it believes historically belongs to it, is motivated by different forces, emerges from different international circumstances and demands different grand strategic responses than the revisionism of the full-scale global wars and imperial conquest of the past. Noting the differences is crucial.

International relations scholars never tire of pointing out that the international system mirrors the state of nature, marked by anarchy. But not all states of nature and anarchical circumstances are the same. It would be absurdly ahistorical to suggest that the drivers, features and rules of the international system today are precisely the same as 1648, 1914 or 1939.

In The Taming of Scarcity and the Problems of Plenty, I suggested two different natural worlds where there was no recourse to a legitimate arbiter or sovereign. The first was an island with terrible weather and uninviting landscape, filled with predators, containing only enough basic resources to barely support its population. The dynamics of that world mirrored the Hobbesian hellscape of a war of all against all.

But imagine another island possessing an inviting landscape: a mild, temperate climate, abundant food, resources and easy shelter, with no predators. The residents enjoy security, satiety and comfort. It would have different governing challenges. On the Hobbesian island, disputes over who controlled scarce resources would dominate. On ‘Love’ island, on the other hand, resources are plentiful.

Picture a scenario, however, where discarded carcasses of abundant animals and fruits draw insects that spread disease and create a public health epidemic: a crisis of the commons. This would be marked by ‘problems of plenty’, generating different circumstances, tradeoffs, dilemmas and solutions than the island of scarcity. Not all states of nature and anarchy are created equal.

During the late 19th through the middle of the 20th century, much of the world – especially in Europe – believed it was in the Hobbesian world of scarcity, marked by Malthusian and Social Darwinist fears that the globe’s food, energy and housing could not meet the needs of exploding populations. Security and information were scarce. States and empires believed acquiring territory, resources, and markets through whatever means possible, including violent conquest and exploitation, even elimination of conquered peoples, was justified in the name of survival. Between 1914 and 1945, between 150 and 220 million people died in wars or were killed by ensuing civil wars, revolutions, famines and epidemics. While unacceptably high, the number of deaths caused by war has been an order of magnitude less in the 80-plus years after the Second World War ended.

This ‘chilling’ of revisionism in the postwar era may have masked other, equally profound changes in the global system that made this kind of total war unappealing, even without the presence of the United Nations, the bipolar Cold War and ensuing unipolarity or nuclear deterrence. The absence of global war is often attributed primarily to the revolutionary consequences of thermonuclear weapons. While no doubt important, four other revolutions played equally critical roles in tempering the Malthusian, Hobbesian forces that tormented the world in the first half of the 20th century and drove conflict.

First, an unexpected and voluntary demographic compression unfolded in the developed world, with birth rates falling precipitously while life expectancy expanded markedly – doubling over the last century. As median ages increased and population growth slowed, the need to conquer additional territory abated.

Second, an economic-technological revolution emerged that massively improved agricultural yields and the availability of food, dramatically boosted industrial productivity and transformed finance capitalism, while improving transportation, housing and health, and making accessible, affordable fuel bountiful.

Third, an information revolution unfolded, whereby increased literacy and technological change significantly expanded communication and access to knowledge about the world (including adversaries, decreasing worries about enemy capabilities and surprise attacks).

Fourth, leaders of the developed world created domestic and international governing institutions and management practices, which, among other benefits, generated far greater domestic stability and socio-economic well-being, eliminated great depressions and provided increased personal as well as collective security, creating a political order that prized order, sovereignty, and, in time, human rights.

Why does this matter for revisionism? The contemporary international system, our current ‘state of nature’, is profoundly different to the system that shaped world politics in the first half of the 20th century. These revolutions of plenty combined to reduce the shadow of famine, disease, and misery that had long fallen upon the human experience, massively increasing total wealth and information, immeasurably improving the quality and length of life in the developed world while weakening core drivers of territorial expansion. Populations urbanised, stabilised and aged; personal and communal security dramatically improved; food, resources and markets became more abundant; and disintermediated flows of information exploded. Knowledge, technology, superior governance and management, and innovation replaced land as the key source of power. Total war, formal empire and conquest no longer made as much sense as they did a century ago.

While a world of plenty did not eliminate all the drivers of revisionism, it is important to distinguish different varieties. The institutions, grand strategies, norms, even conceptual models that emerged after the Second World War were developed to understand and constrain the most extreme form of revisionism: formal colonialism and fully mobilised, ideologically driven, and industrialised world wars of conquest. The underlying logic for that kind of extreme revisionism has, arguably, dissipated, but other forms of revisionism remain: namely irredentism, or the desire to reclaim lost territories and populations (or rights and privileges) that a state thinks were unfairly taken from it. While total, industrialised war is historically rare, irredentism has been a persistent feature of world politics.

Why does this distinction matter? A world of total war, conquest and formal empire obviously demands different grand strategic responses than one shaped by more traditional irredentism. Take two current ‘revisionist’ powers, Russia and China. They are no doubt authoritarian and aggressive, flouting international norms and law and challenging the rules of world order. Do Putin’s Russia and Xi’s People’s Republic of China, however, share the global, expansionist ambitions of the Soviet Union, Nazi Germany or Imperial Japan? If they did, would they have any plausible route to achieving their aims? Or are each seeking instead irredentist claims, to territories – Ukraine and Taiwan – that each believes were unfairly denied to them and are rightfully theirs?

There is room for rigorous debate on this question; revisionism of any sort, even irredentism, may be condemned, deterred and potentially reversed. But a China or Russia motivated by traditional irredentism, as opposed to the global conquest of Nazi Germany or Imperial Japan, would suggest different grand strategic responses. Similarly, one should explore whether China and Russia wish to exploit the current global order for their own purposes or overturn it and replace it with a completely new one of their own.

There are obvious critiques to the distinction. How does one know, ex ante, the difference between irredentism and imperial conquest? France’s desire to recapture Alsace and Lorraine – an irredentist claim – played no small role in the facilitating of the First World War. Hitler’s desire to reincorporate German-speaking territories such as Austria and the Sudetenland mistakenly seemed, at least to some, irredentist at first. It may not be possible to distinguish between irredentism and imperialism, or even revanchism, a desire more fuelled by revenge and the wish to reverse a military defeat. Definitions may lie in the eye of the beholder.

Second, might the appetite grow with the eating? In other words, if Russia had successfully conquered Ukraine, might it have targeted the Baltics or even NATO territories next? Would successfully obtaining Taiwan embolden the PRC to expand throughout East Asia, and even globally? This cannot be ruled out.

Third, for those that are the targets of revisionism, does it matter if it is motivated by irredentism, revanchism, or imperial conquest?

The key point is that the international environment China and Russia (and other potential revisionists) are operating in is much different today than that of the first half of the 20th century. Their populations are decreasing, not exploding, and new territory is not needed to feed or house their citizens. The utility of military force has clearly decreased in the 21st century, as America’s failures in the greater Middle East and Russia’s stalled campaign in Ukraine reveal. While Taiwan’s extraordinary semiconductor industry would, should it survive a PRC takeover, add to its power, it’s hard to see how a successful conquest of Ukraine would dramatically increase Russia’s strength. Acquiring the wheat, coal and a supplicant population in the Donbas added to its power in the past, but no one thinks wheat or coal generate power in 2026, and the population would be far from servile. Even in the absence of existing or future nuclear deterrence, it is hard to imagine China successfully conquering Japan, India or even Vietnam, with whom it lost a border war in 1979. Russia’s performance in Ukraine hardly suggests potential success against the rearming states of Europe. The costs of occupying an angry, dissatisfied population are arguably higher today than in the past.

To be clear, the argument is not that we should accept revisionism, even irredentism. Russia’s brutal invasion and behaviour should be resisted and reversed. China’s aggressiveness should be called out and countered, and there are a multitude of compelling reasons why it should be prevented from taking Taiwan by coercion or force. But effective grand strategy requires interrogating assumptions while generating an accurate picture of the international environment. Basing policies on a world of scarcity, where revisionism often meant formal empire, conquest, extreme ideologies, full mobilisation, hyper-nationalism and total war, risks panic and poor decisions.

The tools of effective power are far different today than they were in 1930, and the current environment may allow room for greater reliance on diplomacy, both public and traditional, attractive power, economic statecraft and technological innovation. The norms of sovereignty, tolerance and human rights, observed in the breach in 1900, have a greater global normative and institutional salience today. Older, urbanised, educated and shrinking middle-class populations, with fewer offspring to spare and possessing greater access to global information, products, and services, may be less supportive of the costs and sacrifice that total war and empire entail.

Postwar western alliances, though challenged, possess deeper capabilities and greater vibrancy than is often recognised, and are certainly far more powerful and resilient than the so-called Axis of Adversaries populated by Beijing, Moscow, Pyongyang and Tehran. Nuclear deterrence – even extended deterrence – remains robust against the threat of invasion and conquest.

We no doubt face threats and challenges, including states seeking to revise boundaries and global rules. To succeed without disaster, we must recognise how the international system has changed and respond accordingly.