Ukraine and the long arc of the history of war

History opens with an unsettling observation: when there is no effective common power to arbitrate disputes, people prepare to harm one another, and frequently do. Thomas Hobbes described that pre-political condition as a “war of every one against every one”, a situation in which fear, uncertainty, and the licence to pre-empt create a standing disposition to violence. His prescription was stark: only a sovereign strong enough to monopolise legitimate force can calm that disposition.

Two centuries later, Carl von Clausewitz reframed the same insight for the age of modern states. War, he wrote, is not an aberration that sits outside politics but “a continuation of policy by other means”—a set of violent instruments employed when leaders judge that coercion will better secure their interests than bargaining will. The implication is not that war is inevitable, but that it is intelligible as purpose-driven action inside political life, not beyond it.

A third canonical strand comes from Charles Tilly’s account of European state formation: rulers who could extract capital and marshal coercion survived; those who could not were conquered or dissolved. In his blunt formula, “war made the state and the state made war.” Over centuries, states professionalised soldiers, built fiscal-military machines, and embedded violence inside bureaucratic routines. This did not make war constant, but it made the capacity for organised killing durable, legitimate, and—crucially—administratively scalable.

These three lenses—Hobbesian anarchy, Clausewitzian instrumentality, and Tilly’s coercion-capital bargain—explain why war recurs even when individuals abhor it. Yet they do not exhaust the causes. The deeper arguments about human nature and culture cut in different directions. Azar Gat and Lawrence Keeley marshal archaeological and ethnographic evidence that warfare shadowed humanity long before cities and kings, implying an evolutionary and material logic for intergroup violence. Detractors counter that such evidence is partial and that many small-scale societies show low rates of lethal conflict; Margaret Mead argued provocatively that war is a cultural invention that can in principle be disinvented. What emerges from this debate is not consensus but a caution: neither biological determinism nor cultural idealism suffices. The propensity for organised violence appears contingent—encouraged by certain environments and institutions, restrained by others.

Modern quantitative histories add yet another twist. Steven Pinker collates centuries of data to argue that violence—including war—has declined over the very long run, thanks to state monopolies on force, commerce, literacy, and cosmopolitan norms. Critics object that his series can underweight catastrophic tail risks, rely on disputed prehistoric baselines, or conflate Western with global trends. Still, even his critics accept that institutions and ideas matter: how we organise power and how we think about strangers helps explain why violence sometimes ebbs.

If the canonical thinkers tell us why war can recur, realist international relations theory tells us when states are most likely to reach for it. Kenneth Waltz’s “third image” places the ultimate cause of war in an international system without a sovereign: anarchy rewards vigilance and power accumulation. John Mearsheimer’s offensive realism presses further: great powers, uncertain of others’ intentions and lacking an umpire, will often try to maximise their relative power and, when they see opportunity, expand. These models are intentionally spare; they do not excuse aggression, but they predict when aggressors may appear and why neighbours must prepare.

Historical ethics, from Thucydides onwards, help us name the motives at work: fear, honour and interest. The Melian Dialogue is not a manual but a warning: when the strong persuade themselves that necessity erases morality, they often overreach and come to grief. The lesson is less that power is wicked than that power without prudence and law corrodes judgment—an admonition as old as Athens’ Sicilian expedition and as current as Moscow’s stalled hopes for a quick victory.

How does this bear upon the war in Ukraine? First, the initial casus belli fits the realist schema and the historical warnings. Russia’s leadership—animated by a mix of imperial nostalgia, fear of a democratic, Western-leaning neighbour, and the interest in controlling Black Sea access and Ukraine’s industrial heartlands—chose to revise borders by force. In Clausewitzian terms, war became the instrument of a political project: to subordinate Kyiv and re-order Europe’s security map. The choice also reflects Hobbes’s grim logic at the systemic level: in the absence of a supranational sovereign capable of compulsory adjudication, Moscow gambled that violence would serve its policy better than law. The swift, self-defensive mobilisation of Ukrainian society and the coalition backing her was the reply of a people and an interstate order unwilling to concede that premise.

Secondly, the conduct of the war shows how institutions and technology shape the scale and character of killing. Industrial-era massed armour and artillery returned, but so did a new layer of cheap autonomy and precision: first-person-view and loitering munitions that extend the reach of small units, saturate air defences, and collapse the cost of entry into strike warfare. Analyses by RUSI, RAND and others describe how ubiquitous drones now complement artillery, complicate manoeuvre, and multiply the lethality of otherwise static fronts. In short, the means of killing have become more distributed and adaptive even as the battlefields have become more positional.

Thirdly, the war illustrates Tilly’s old bargain in real time. Both sides have reorganised economies and bureaucracies to feed the front with bodies, shells, electronics and repair capacity. Russia has raided Soviet-era stockpiles and ramped up drone production and imports; Ukraine has fused together a wartime tech sector with volunteer logistics to field thousands or even millions of small strike systems. War, here as in early-modern Europe, is remaking the state: tax codes, procurement regimes, and civic identities are being refashioned to sustain the coercive enterprise.

Fourthly, attrition is not the absence of strategy; it is a strategy chosen under constraint. As Michael Kofman argues, Ukraine’s viable path in phases of limited mobility has been to erode Russian combat power faster than Moscow can reconstitute it, by leveraging precision, drones and Western-supplied fires while hardening her own force against Russian strikes. This theory of victory accepts that manoeuvre is episodic; the operational art lies in creating the conditions—degraded logistics, thinned air defences, brittle command—for manoeuvre to matter when windows open.

Finally, the moral dimension is not epiphenomenal. William James worried that the “strenuous” virtues that make nations willing to pay war taxes can seduce societies into confusing sacrifice with wisdom. That is why law and alliance—Europe’s long attempt to tame Hobbes’s state of nature—matter so much. If Pinker is even partly right that violence recedes where states monopolise force under law and where commerce, literacy and cosmopolitanism thicken, then Ukraine’s wager—to remain a constitutional state at war and a market society under siege—is not only strategically sensible but historically potent. It aligns her cause with the long, uneven work of bending power under rules.

What, then, explains the long, bloody ledger of human history—and why does it illuminate today’s war?

• The structural condition: In an anarchical world, security dilemmas, misperception and opportunism recur. Without a superior enforcing authority, rulers sometimes calculate that war pays. Hobbes, Clausewitz and modern realism all capture facets of this iron logic.

• The institutional ratchet: States that mastered coercion survived and were imitated. The technologies and bureaucracies that enable mass violence are cumulative and sticky; once built, they seek tasks. Tilly’s Europe is a cautionary parable for the twenty-first century.

• The cultural argument: War is neither biologically fated nor easily abolished. It is an invention that can be normalised or delegitimised. Norms, commerce and cosmopolitanism can throttle its appeal, but only if backed by credible power. The debate running from Mead to Gat and Pinker reminds us that restraint is made, not found.

• The technological frontier: Innovations that lower the cost of lethality or widen access—gunpowder, railways, machine-tools, drones—reshape killing’s arithmetic. Ukraine’s skies of cheap uncrewed systems show how quickly a battlefield equilibrates around a new means of destruction.

• The moral warning: Appeals to necessity, honour and fear can license folly. Thucydides’ dramatised Athenians were not sages but a mirror held up to power; the point was not to celebrate ruthlessness but to show how it unmans prudence.

Ukraine stands at the junction of these currents. The Kremlin’s decision to use war as policy was intelligible in realist terms and condemnable in legal and moral ones. Ukraine’s resistance is intelligible in exactly the same frameworks: a sovereign people, denied security by aggression, appealing to law and alliance while mobilising society and technology to deny the aggressor’s bet. The historical record does not promise quick deliverance; it does suggest that political communities that can align material power, institutional stamina and moral clarity often outlast revisionist projects whose violence outruns their prudence.

If the history of humanity is so crowded with killing, it is not because we are doomed to it, but because the incentives for rulers to gamble with lives have so often exceeded the checks upon them. The remedy—never simple, never swift—is the hard, layered work of building domestic legitimacy, international law with teeth, and coalitions willing to enforce it. That is the wager being made today from Kyiv to Kharkiv: that the best way to reduce the place of killing in human history is to prove, in this case, that it does not pay.