by David Polansky and Daniel Schillinger
August 03, 2026
from AEON Website


 

Bronze helmet,

 c460 BCE, classical Greece.

Courtesy the British Museum



Far from thinking that 'might makes right',

the great historian's analysis of war

identifies a vice common to all states...

It's almost never a good sign when Thucydides is in the news.

The ancient Greek historian of the Peloponnesian War is typically invoked either to alert us to the possible return of a bygone age of terrifying great-power conflict, or to confirm that strong states can and should advance their own material interests, irrespective of justice.

Earlier this year, the Canadian prime minister Mark Carney earned much acclaim when he quoted, at Davos, the most famous lines in Thucydides' History of the Peloponnesian War:

'The strong can do what they can, and the weak must suffer what they must.'

While Carney intended his reference to be a critique of US behavior under the Trump administration, Thucydides is also invoked in defence of aggressive or even imperialistic policies, especially in the United States.

Yet those who look to Thucydides for either a justification or a critique of empire should be disappointed.

Thucydides pulls no punches:

he writes to expose the delusions of both the strong and the weak, the unjust and the just.

Self-deception is a leitmotif of his History.

Because self-deception is perennial, and because it can prove disastrous to victors and vanquished alike, Thucydides' work remains timely and timeless, as he expected it would.

Thucydides introduces himself, at the outset of his work, as an Athenian who 'wrote up' the war between the Athenians and the Peloponnesians because he judged this war to be the greatest war, surpassing all prior wars, including the Trojan War (all references to Thucydides are to the Richard Crawley translation, with our own modifications where appropriate).

The duration of the war contributed to its greatness, persisting for 27 years, from 431 to 404 BCE.

Thucydides foresaw the enormity of the conflict, which began with its principal combatants,

Athens and Sparta,

...at their peak as the Hellenic world's greatest naval and land powers, respectively.

Sparta had been, for centuries, the pre-eminent Greek polis.

But, following the Greeks' repulsion of several attempted invasions by the Persian Empire (collectively known as the Persian Wars), Athens had established a powerful maritime confederacy.

Over time, Athens transformed this ostensibly defensive alliance into an empire over a sizeable part of the Hellenic world.

Eventually, Sparta was induced, by its own Peloponnesian allies, to declare war against Athens, ostensibly for a number of pretexts but, in reality, to check Athenian expansion.

Over its course, the war between the Athenians and the Peloponnesians would sweep up many smaller Greek cities, not to mention the Persian Empire and assorted non-Greeks.

Ultimately, Athens would be defeated, and its empire dismantled, events which Thucydides survived long enough to witness but not to recount in his History...
 

Thucydides' 'History'

elicits a range of searching reflections

on war's causes and consequences...
 

The line Carney invoked is often associated with 'realism' in world politics.

This is a somewhat woolly term that encompasses both a moral position of skepticism about,

the possibility of justice in political life and an analytical approach to understanding political events in terms of material power and interest.

Thucydides is a plausible originator of realism inasmuch as he offers an unvarnished and unsentimental account of the operation of political power among Greek cities.

His realism may be contrasted with the 'liberal institutionalism' of a thinker such as Immanuel Kant, who holds out hope for mutual cooperation and even perpetual peace among states.

During the 20^th century, these lines of ideological disagreement came to define discussions of international politics in both academic and political discourse.

For example, the British historian E.H. Carr warily observed, during the Second World War, the spread of what he called 'utopianism', as reflected in the excessive hopes that,

international institutions such as the League of Nations might foster world peace.

In response, Carr offered a qualified defence of realism for providing a pragmatic and flexible guide to politics in a dangerous world:

'realism is the necessary corrective to the exuberance of utopianism, just as in other periods utopianism must be invoked to counteract the barrenness of realism.'

Thucydides' own relationship to realism is more ambiguous than his reputation might suggest, however.

For one thing, he never uses the term itself (which does not much predate the 20^th century - in fact, it was Friedrich Nietzsche who first applied the term to Thucydides). He also rarely issues judgments under his own name.

Many of the most notorious lines in his History are spoken by historical figures.

Would anyone suppose that lines spoken by Richard III contain clear statements of William Shakespeare's own views?

No doubt, Thucydides provides ample material for those who hope to find realist perspectives in his work.

It is also true, however, that his History elicits a range of searching reflections on war's causes and consequences. Note that Thucydides emphasizes, humanely,

the suffering occasioned by the Peloponnesian War...

Some of this suffering was caused by disasters coinciding with war, not least the plague at Athens, which killed as many as a quarter of Athenian citizens by 425 BCE.

But much suffering was caused by the Greeks themselves, including the Athenians and Spartans, whom one might have thought too 'civilized' to become so violent.

In Thucydides' words:

'Never had so many cities been taken and laid desolate... never was there so much banishing and blood-shedding, now on the field of battle, now in factional strife.'

Thucydides himself was hardly exempt from events that shook the Hellenic world.

He suffered from the terrible plague that struck Athens.

 

He served in the war as an Athenian general, only to be exiled by his fellow citizens as punishment for failing to prevent the revolt of Amphipolis in 424 BCE.

Yet Thucydides writes about the war with sobriety and restraint.

There is little editorializing in his History; the author all but effaces himself.

Thomas Hobbes, who was the first to translate him directly from Greek to English, observes:

'Thucydides is one, who [does not] digress to read a lecture, moral or political, upon his own text, nor enter into men's hearts further than the acts themselves evidently guide him.'

It is this same reserve, meanwhile, that seems to invite readers to impose their own interpretations upon the work.

The most well-known line in Thucydides' History - and the one still encountered by undergraduates the world over, not to mention the attendees of Davos - is the one delivered by the Athenians to the Melians:

'The strong do what they can and the weak suffer what they must.'

This episode, the Melian Dialogue, occurs in 416 BCE (more than halfway through the war), when the Athenians send an expedition to the neutral island of Melos to compel the Melians to submit to Athenian rule.

Prior to the siege, nameless representatives from both cities meet for parley.

Note, however, that the standard translation of the famous line is more ominous than the Greek verb, συγχωρέω, really warrants.

A more accurate rendering of the line would be:

'Those who are superior do what they can, and the weak yield.'

Perhaps the translation issue explains, in part, why many readers suppose that the Athenians here say that,

'might makes right.'

What the Athenians actually say is that,

the language of justice only has a place in negotiations among relative equals in power.

Between the powerful Athenians and the weak Melians, the Melians must yield to Athenian interests.

So, even if the Athenians' line contains a threat, it also invites the Melians to speak without pretences.
 

For many readers,

the Athenian disaster in Sicily

represents punishment

for the annihilation of Melos...
 

The Melians reject this offer to find common ground on the basis of shared interests.

Although we do not hear from the Melian people but only from their oligarchic rulers, these announce that the Melians will fight the far-more-powerful Athenians, even as the Athenians ask only that the Melians become tributary allies of Athens, supporting the Athenian empire with cash and ships.

The Melians even seem to expect that they will defeat the Athenians - because they will receive the help of the gods (as just men) and the Spartans (as Spartan colonists).

In their own words:

'We trust that the gods may grant us fortune as good as yours, since we are just men fighting against unjust, and that what we want in power will be made up by the alliance of the [Spartans], who are bound, if only for very shame, to come to the aid of their kindred.'

The Athenians explain to the Melians that neither nature, the gods nor the Spartans will protect them:

'As you have staked most on, and trusted most in, the [Spartans], your fortune, and your hopes [for justice], so will you be most completely deceived.'

And the Melians were deceived:

the Athenians destroyed the island, killing all the men and enslaving the women and children.

The Athenians would soon suffer a similar fate...

On the heels of the Melian massacre, within six months' time, the Athenians would launch an expedition to Sicily, ending in the total destruction of their forces - about 40,000 men, the size of a whole city.

For many readers,

the Athenian disaster in Sicily represents punishment for the annihilation of Melos.

In one of his rare direct statements on the war, Thucydides himself declines to blame its outcome on any particular military encounter - not even the Sicilian expedition - nor upon the Athenians' pursuit of empire.

More broadly,

the Athenian response to the Melians holds true for other cities.

There is nothing in Thucydides' History that refutes the Athenians' central claim:

the strong are simply in a greater position to impose their preferences, which the weak disregard at their peril.

Every city rules to the limits of its power.

The question, rather, is whether any city does so wisely, without illusions.

What, after all, did the Athenians gain - except infamy - by destroying tiny Melos?

 

Why did the Melian rulers prevent the Athenians from speaking to the people, and why did they insist on self-destruction when they needed only to pay tribute to Athens?

The pathos of the Melian dialogue, for Thucydides, lies in the self-deceptions of both the Melians and the Athenians - and the disastrous consequences to which these give rise.

The Melians represent one instance of a broader psychological phenomenon depicted by Thucydides:

a fervid attachment to justice, especially in times of war, can carry with it certain delusions.

In Thucydides, the just are self-deceived, both because they think that they will prosper on account of their justness, and because they overrate their own attachment to justice.

Sparta is a case in point...

The Spartans and their allies insist on the justness of their war against Athens. To hear them tell it, the Athenian empire imposes slavery on its subject cities, since these are compelled to contribute tribute and ships to Athens.

By contrast, the Spartans call themselves,

'the liberators of Hellas'...

This rhetoric of justice masks the Spartans' true motivations, which Thucydides unmasks.

Thucydides comments on the Spartan decision to declare war against Athens in the first place:

'The [Spartans] voted that the treaty had been broken, and that the war must be declared, not so much because they were persuaded by the arguments of the allies, as because they feared the growth of the power of the Athenians.'

While the Spartans denounce the injustice of the Athenians and proclaim the freedom of all Greek cities, they act as they do because they see their own hegemony on the Peloponnesus threatened.

At the very moment the Spartans vote for war and prepare to invade Attica, they remain nominally in treaty with the Athenians.

Evidently the Spartans do not care about the injustice of breaking the treaty so much as they care about protecting their interests, whatever they may think or say - though they do make sure to say, as a pretext, that the Athenians have broken the treaty.

The Spartans are moved by a passion for justice, which burns hot when they mete out punishment

The Spartans also commit many of the worst atrocities reported by Thucydides.

They butcher all sailors, even those from neutral cities, caught sailing near the Peloponnesus at the start of the war.

 

In 427 BCE, they execute some 200 Plataeans and raze the city of Plataea to satisfy the wishes of their own strategic ally, Thebes.

 

In 417 BCE, the Spartans annihilate the city of Hysiae, killing all the male inhabitants and enslaving the women and children.

Most egregious, perhaps, is the Spartans' massacre, in 425 BCE, of their own helot slaves.

The helots were Messenians and Laconians, neighboring peoples on the Peloponnesus, whom the Spartans had enslaved en masse.

Inviting the helots to pick out those among themselves who had fought most bravely on behalf of Sparta, 2,000 were selected with the promise of freedom.

According to Thucydides:

'The Spartans, however, soon afterwards did away with them, and no one ever knew how each of them perished.'

At best, the Spartans are hypocrites, trumpeting the causes of justice and liberation while quietly acting out of fear and self-interest.

Yet the truth is worse and more complicated.

The Spartans are moved by a passion for justice, which burns hot when they mete out punishment.

 

Those who threaten the interests of the city - including their own best slaves, whose only fault is their excellence - incur the wrath of the Spartans.

They are self-deceived because they do not seem to realize that their passion for justice has grown into a monstrous taste for punishment...

The crimes of the Spartans receive a fraction of the attention paid to the fate of the Melians, partly because the Spartans committed their atrocities without the Athenians' famous (or infamous) rhetorical flourishes.

Meanwhile, the Athenians may appear not to be self-deceived. After all, they talk tough about the weakness of justice in affairs among cities, and aren't shy about pointing it out to others.

In a conference at Sparta before the outbreak of the war, envoys from Athens offer a tripartite defence of the Athenian empire.

First, human passions - especially fear, but also desires for honor and profit - compel cities to rule to the limits of their power.

 

Second, experience confirms this account of the psyche. Only weaker cities appeal to justice; the strong simply act, securing their interests as they can.

 

Third, because human nature and experience together compel cities to seek expansive rule, no city should be blamed for so acting. Necessity excuses the Athenian empire.

Yet, Thucydides exposes the delusions of the Athenians no less than those of the Spartans.

If the Athenians grasp the weakness of justice among cities, they overestimate the power of reason - including their own. It was the Athenians, after all, who insisted on a dialogue with the Melian elites, trusting (mistakenly) that they would be able to persuade the Melians to accept Athenian rule.

By destroying the island in the end, the Athenians school the Melians in the weakness of justice, but they commit two blunders of their own:

they lose the resources that Melos might have provided to their empire; and their massacre of the people hurts their reputation as the ally of the people in oligarchic cities.

For all their vaunted realism,

the Athenians make bad decisions,

or fail to understand their own motivations...
 

Likewise, in the war conference at Sparta, the exposition of the Athenian position works not at all to dissuade the Spartans from declaring war (indeed, it seems almost calculated to enrage them).

Again and again in the History, the Athenians browbeat their enemies at the bargaining table. It is unclear whether the Athenians care more about realizing their strategic aims or vindicating their own cleverness.

It is not enough, in other words, for the Athenians to realize their ambitions; they also want the satisfaction of seeing the other cities acknowledge the truth of their worldview.

But its truth should not require other cities to grasp it. Silent conquest would work just as well - or better, insofar as it avoids needlessly offending those whose acquiescence would be of benefit to them.

Finally, for all their vaunted realism, and even when they focus their deliberations on material realities,

the Athenians make bad decisions, or fail to understand their own motivations.

For example, when the Athenians decide, under the influence of the charismatic Alcibiades, to invade faraway Sicily, there is surprisingly little discussion of the actual strategic value of this venture.

Rather, the citizens of Athens vote as they do for a variety of more personal incentives, with the older men seeing opportunities for vicarious victory, and the young seeking glory and adventure with little fear for their lives.

And yet, as though mistrusting their own judgments, they elect to place the cautious Nicias in charge of the expedition, as if his personal moderation would somehow balance out their immoderate goals.

In the event, this mismatch leads to disaster...!

More broadly,

this misunderstanding of their situation extends to the nature of their empire itself.

Pericles, the pre-eminent Athenian statesman, admits that the Athenian empire is 'like a tyranny'.

Yet he does so only in the final speech (before his death), with the plague raging through his city. Even then, he cannot help urging the Athenians to hope for glory. He claims that, even in defeat, Athens will be remembered for having ruled over more Greeks than any other city.

In one sense, at least, Pericles was not mistaken:

we do still recall the exploits of the Athenians...

Yet our remembrance is owed less to Pericles than to Thucydides.

But, where Pericles poetically declares that,

'heroes have the whole earth for their tomb',

...Thucydides depicts the end of the Sicilian expedition:

the Athenians leaving behind the unburied and the wounded, drinking their own blood in the river Assinarus, and dying, ignominiously, in the stinking quarries of Syracuse.

And where Pericles promises his fellow citizens that they will leave behind them 'imperishable monuments', Thucydides leaves us his far more ambiguous History of the war.

Thucydides saw in the Peloponnesian War,

'a rough master, that brings most men's characters to a level with their fortunes'.

Observing the United States' present conflict with Iran, which has increasingly severe implications for the global economy, it is evident that,

those who embarked on the war had outsized expectations of success at minimal cost, and the tough talk that accompanied its outset was a reflection of those same expectations rather than a true apprehension of events.

This kind of faux-realism has a way of excluding the subject from the harsh logic of their own claims about political life.

Meanwhile,

others routinely predict the decline of US power as a cosmic punishment for its repeated aggression against other countries.

While decline may be inevitable over a long enough timeline, the many announcements of it are also a form of wish-casting for a just universe, in which the unjust inevitably receive their comeuppance.

After referencing Thucydides, Carney offered some tough-minded talk of 'middle powers' banding together, which was rather vague on actual power analysis:

How sure are we that these states really do constitute middle powers (as opposed to small ones)?

 

And what do their aggregated capacities really amount to?

A similar self-deception pervades the Hellenic world throughout the war.

The Athenians deceive themselves as to their true capacity to rule over their fellow Greeks, especially as to the power of their reason to control events and persuade others.

And they even go so far as to deceive themselves as to how their exploits will be remembered by those they conquered.

The Spartans deceive themselves as to the justness of their cause, no matter their own acts of manifest injustice.

Finally, the Melians deceive themselves that their own just cause in facing a stronger invader will be rewarded through salvation by either their Spartan allies or the gods themselves.

By contrast, Nietzsche accords Thucydides the highest praise for his,

'unconditional will not to deceive [himself]'.

He sees the world as it is, and he does not attempt to find in it confirmation of what he already believes he knows.

Thucydides' self-knowledge defines the distance between him and us, which is not merely temporal but psychological.

It is ironic, then, that so many with greater confidence and less self-awareness apply their own purposes to a work concerned with the vast human capacity for self-deception...!