Everybody Wants a Thucydides Trap


This post was originally published as part of the Thucydides Roundtable project over at Zenpundit. I encourage you to read all of the posts in the roundtable. 

All the world trembles at the dreaded “Thucydides trap.”

Of late this phrase has been all the rage. It was first popularized by Graham Allison in 2012, and has only become more popular since. Read American debates about China’s future, and you will see it; read Chinese debates about America’s future, and you will find it there as well. On the lips of all is Thucydides’ famed assessment of the origins of his war. It might be the punchiest pronouncement of the entire book:

The growth of the power of Athens, and the alarm which this inspired in Lacedaemon, made war inevitable. (1.23.5)

It is not clear to me that Thucydides intended this theory to be a general theory of why all great powers go to war, though many take it this way. The other famous phrase from this book—the Athenian declaration that they were motivated to build their empire by “fear, honor, and interest” (1.76)—has a far better claim to this title, followed as it is by the note, “it has always been the law the weaker should be subject to the stronger.” Thucydides invokes no laws in his famous one liner on the “real cause” of the war. Notice too that only one leg of his trinity is invoked to explain the Spartan decision for war. Were Thucydides serious about conflating the cause of this war with the cause of all wars, it would make sense to include the other two legs in his explanation.

But whether or not Thucydides hoped his statement might be a template for all time, it is being treated as such. Here it used to explain all great power wars of the last four centuries:

Graphic created by the Harvard Belfer Center’s “Thucydides Trap Case File” page


This roundtable’s journey through Thucydides’ History gives us the chance to assess whether the   “Thucydides trap” metaphor helpfully explains the historical events it is drawn from. To approach this question is to first ask another: can we untangle the events of the war itself from the narrative of the man who chronicled it? This is the  issue at the center at this post; no one can appraise the work and words of Thucydides without carefully working through it.

Thucydides is celebrated today as a man who articulated and developed grand principles of politics and conflict. However, Thucydides was not an explicit theorist of war. His book has themes, not theses. He does not prove, but impresses. These impressions are made through narrative art. The order in which Thucydides introduces ideas and events has great meaning; the amount of space he devotes to some events (but not to others) changes how readers perceive them. These subtle decisions of placement and length develop Thucydides’ main themes far more powerfully than his occasional editorial comments. Perceptive readers of Thucydides time, aware of the narratives Thucydides hoped his work would displace and familiar with the events he passes over, would understand exactly what Thucydides was doing. With us the challenge is harder. We don’t come to Thucydides’ History with preexisting knowledge of the war. Our only guide to Thucydides is Thucydides himself. We thus must read with utmost care. If we do not, we risk mistaking Thucydides’ judgments about the war for the events of the war itself.

Nowhere is more careful attention demanded than Thucydides’ treatment of the Megarian Decree. Like all Greeks of the age, the Athenians had long memories. Their enmity for Megara began a generation earlier, when Athenian blood was lost as consequence of Megarian betrayal. The Megarian betrayal came during a day of war, Athen’s first life-and-death struggle with the men of Sparta. The proximate causes of the this dispute were more recent, however. Thucydides reports that Athens “accused the Megarians of pushing their cultivation into consecrated ground and the unenclosed land on their border, and of harboring runaway slaves.” Thucydides’ description of the Athenian response: a “Megara Decree, excluding the Megarians from the use of Athenian harbors and of the market of Athens.” (1.139.2)

The Megarians declared that this degree stood “in defiance of the treaty (1.67), and the Spartans apparently agreed. The decree was the price of peace; the Spartans informed the Athenians that “war could be prevented if they revoked the Megara decree” (1.139.2) and it was on the question of whether or not to revoke the decree (for, said those against it, there was “folly [in] allowing it to stand in way of peace” (1.139.4). In face of these questions Pericles was dismissive:

I hope that none of you think that we shall be going to war for a trifle if we refuse to revoke the Megara decree, which appears in front of their complaints, and the revocation of which is to save us from war, or let any feeling of self-reproach linger in your minds, as if you went to war for slight cause. Why, this trifle contains the whole seal and trial of your resolution. If you give way, you will instantly have to meet some greater demand, as having been frightened into obedience in the first instance; while a firm refusal will make them clearly understand that they must treat you more as equals. Make your decision therefore at once, either to submit before you are harmed, or if we are to go to war, as I for one think we ought, to do so without caring whether the ostensible cause be great or small, resolved against making concessions or consenting to a precarious tenure of our possessions. For all claims from an equal, urged upon a neighbor as commands before any attempt at legal settlement, be they great or be they small, have only one meaning, and that is slavery. [1.40.4, emphasis added]

The argument that Thucydides puts into Pericles’ mouth is simple: the coming war is not really about the decree at all, but more fundamental questions of power and rank. Is Athens subordinate to Sparta? Or are the two polis equal in rank? That was the real question being decided by this war. Any “ostensible cause” to get things rolling would do—in this case that ostensible cause just happened to be the embargo of Megara.

Readers will notice a similarity between Pericles’ talk of “ostensible causes” and Thucydides’ earlier distinction between “immediate” and “real“ causes of the war. This cannot be coincidence, though it is difficult to tell if Thucydides places this argument in Pericles’ mouth to strengthen his own argument about the cause of the war, or if Pericles’s understanding of the war’s origins is part of the reason Thucydides admires him so. By the time Pericles made this statement he was probably correct. That the Spartans hoped to use the issue as a stand in for the competition between the two polis was proven by the uncompromising demand that followed it:

“”Lacedaemon wishes the peace to continue, and there is no reason why it should not, if you would leave the Hellenes independent.” (1.39.3)

But how did the Athenians get into this position, handing the Spartans such an easy cause to justify their war with? We do not know. Thucydides’ editorial decisions have made the Megarian decree something of a mystery. The Megarians and the Spartans maintained that the decree was a violation of the treaty of peace, though just how it was a breach in the treaty we are not sure. The Megarians formally listed their reasoning during the 431 conference of the Peloponnesian allies (1.67.4), but Thucydides does not relate the speech, nor tell us anything about it except that it was given. Of the debates that led the Athenians to enact the degree even less is written. We do not, in fact, even know what year the decree was enacted, or whether it came before or after the disputes with Corinth. Though we are told some Athenians argued for its repeal in the face of Spartan demands, their arguments, like that of the Megarians, are only mentioned in a sentence or two of narrative, as mere context for the speech given by Pericles that I have quoted above.

See this for what it is: Thucydides has omitted from his history a central cause of the war! This was not an oversight. It may have been the entire point of Book I. In Thucydidean terms, the Megarian decree was (as Thucydides has Pericles say) “a trifle.” It was an “ostensible cause” of the great war, but not its true one. A war of this magnitude could not be caused by trifles, and to drive home the point of just how trifling and irrelevant this causus belli was to the war’s actual conduct, Thucydides crafts a narrative of the war that does not include it at all. This is clever, and Thucydides’ contemporaries, quite aware of the decree’s details, probably considered the omission quite artful.

While we don’t know the details of the debates surrounding the decree, it is easy to see how reporting those debates in detail might have undermined Thucydides’ narrative. Did the Athenians enact the decree in ignorance of its long-term consequences—was it merely an angry and reflexive response to a localized spat with the Megarians? If that was the case, then many would say that the Athenians stumbled into the war blindly, unaware of the import their actions would have on broader Hellas. What better caricature of bumbling democracy could there be? This image of Athens would serve Thucydides well later in his narrative, but it is at odds with his idealized portrait of Athens under Pericles, a time when “what was nominally a democracy became in his hands government by the first citizen” (2.65). This was the clear-sighted visionary whose guiding hand might have led Athens to victory! Bumbling into a great war does not match the narrative.

On the other hand, if the Athenians knew exactly what they were doing in enacting the decree, then the decree was a challenge—a deliberate attempt to humiliate the Spartans, weaken their alliance, and goad them into war. If this is true then Thucydides’ grand narrative is weakened even more than if the Megarian degree was a simple, bumbling mistake. Sparta’s decision for war would then be less a fearful reaction to forty years of growing Athenian power than a measured response to a deliberate insult.

Thanks to Thucydides, we do not know which of these is the true story. What we do know is that we do not have the true story. We cannot trust Thucydides to give us an honest picture of the past.

The gaps in Thucydides’ account of the Megarian Decree are not unique. They appear again and again in the first book of the History, and creep even into the beginning sections of Book II. Many of these are moments Thucydides would have observed first hand. Thucydides reports that the Athenians debated the alliance with Corcyra twice before agreeing to dispatch two ships to the island’s defense. But his description is terse: “in the first assembly there was a manifest disposition to listen to the representatives of Corinth; in the second, public feeling had changed and an alliance with Corcyra was decided on.” (1.44.3). What the arguments of each side were, and why the public feeling changed so forcefully in favor of Corcyra (perhaps the influence of Pericles?), is never revealed. The debates where the Athenians decided their demands on Potidaea are also ignored. And as mentioned earlier, the speeches against the general war, though noted, are not described in detail. Indeed, in all of Book I’s eighty pages, Thucydides includes only one speech from Athens’s internal debates, the speech in which Pericles declares that Sparta “always had designs against us” and that the time for Athens to go to war in defense of their rank had come, “without caring whether the ostensible cause [for war] be great or small” (1.141.4).

Clever, is it not? Thucydides first book is a polemic. It is designed to prove that this was a war decades in the making, a product of Sparta’s growing fear over Athens growing power. For this scheme to work the growth of Athenian power must seem incessant and inevitable; it must be a trend beyond the control of individual men. But the actual course of events preceding the war suggests that this was hardly the case—before 433 BC, there was a rough balance of power between the two blocs.  Athens was the master of the sea. Sparta was master of the land. With a few exceptions codified during the last peace, Athenian activities were restricted to Ionia and the Aegean. The Athenians had no interests in the Peloponnese, nor on the Adriatic coasts or in Sicily. In these regions their power was not growing. What threat the Athenians presented was to Spartan pride and self-esteem. The Athenians put all of Greece to shame with their massive temples and marble monuments. The Athenians built structures that surpassed Pan-Hellenic temples in Delphi; they hosted festivals no one in Greece could compete with. But until the affair in Corcyra, the Athenians showed no new geopolitical ambitions. The expedition to Corcyra almost did not happen. What if it hadn’t?

It is a question worth asking. Opposition within Athens to the decisions of these years was constant, though it is difficult to know for what reasons this opposition arose. Perhaps it was because many in Athens earnestly did not wish a war with Sparta? If Thucydides’s glowing picture of Athen’s first citizen is to be trusted, it is likely that events proceded as they did only because the leadership of famed Pericles. If Pericles had died years before, would there have been a war with Sparta? Had the opposition kept Athens out the Corcyran affair, would the Corinthians still have dragged the rest of the Peloponnesian League to war? Had the Athenians not directly challenged Sparta through the insult of the Megara decree, would the Spartans have been so eager to listen to the Corinthian call?

We cannot know the answer to these questions. This is no accident: we cannot know the answer to these questions only because Thucydides does not want us to dwell on the answers to them. This suggests that the answers to these questions, if known and considered, would place a dent in his explanation for the war. Thucydides is not a historian to be trusted.

Much more could be said on this theme. The Spartan decision for war seems no more inevitable than the Athenian one. It was Corinthian interests, not Spartan ones, at stake in Corcyra and Potidaea. Sparta could sacrifice these without the loss of anything but face. (Indeed, when the war began it was not clear to the Lacedaemonians that complete control of the littoral to their west and north would have damaged Sparta in any real way. Athens had complete control of the sea during the last war, after all, but she still lost it). The Corinthians had embarked upon a “private enterprise” (1.66) against the Athenians for the sake of “sectional interests” (1.82.6)—e.g., an enterprise whose profits would go to no one but themselves. The Spartans were clearly divided on the wisdom on helping them; it took substantial Corinthian lobbying of all the allies (1.119), direct insults to Sparta (1.68-1.71), two separate councils of war, and, as Joe Byerly has pointed out earlier in this roundtable, a manipulative method of voting, before the the Spartan war party took control. Even then Spartans were slow to act. A little less than a year would pass between the Spartan decision to go to war and the actual waging of it, and it was not Sparta, but her ally Thebes, who fired the first shot. In contrast to the quick moving Thebans, eager to take their enemies by surprise, Thucydides reports that it was not until the Thebans launched their attack on Plataea that the Peloponnesians began to truly “prepare for war.” The Spartans then sent to the Athenians yet another herald in search of peace (2.12), and followed this up by campaigning and marching with special slowness in hope that the Athenians might change their mind (2.18).

The image of Sparta painted here is quite different from that suggested by Thucydides’ claim that the war was waged by a frightened Sparta. The Spartans did not fear the Athenians enough to immediately launch her full fury against Attica before the Athenians had time to prepare a defense. Giving the Athenians a last chance for peace was more important to the Spartans than dealing a crushing opening blow when the war began. Perhaps this is because they thought they could easily defeat the Athenians (in which case, what was there to fear?); perhaps it was because they did not see the war as inevitable at all. The total picture one gets of Sparta on the eve of war is of a people divided, dragged into a war many did not care for because of the machinations of their allies and the deliberate insults of their enemies. It was less fear that drove Sparta to war than honor (see esp 1.86.5); their aim was not to rob Athens of her power, but of her pride.

On this count the Athenians were not so different. Pericles says the Athenians must go to war to prove to the Lacedaemonians—and, we assume, the rest of Hellas—that they were the equal of great Sparta. But this was tacitly acknowledged in the treaty of the Thirty Year’s peace, which divided the Hellenic world into discrete spheres of influence, one led by Sparta, the others by Athens. Only in the immediate years preceding the war did the Athenians do anything that might challenge this arrangement. Why weren’t the Athenians willing to accept this status quo? The answer is not found until Book II, when Thucydides puts the answer into the mouth of Pericles:

Athens alone of her contemporaries is found when tested to be greater than her reputation, and alone gives no occasion to her assailants to blush at the antagonist by whom they have been worsted, or to her subjects to question her title by merit to rule. Rather, the admiration of the present and succeeding ages will be ours, since we have not left our power without witness, but have shown it by mighty proofs; and far from needing a Homer for our panegyrist, or other of his craft whose verses might charm for the moment only for the impression which they gave to melt at the touch of fact, we have forced every sea and land to be the highway of our daring, and everywhere, whether for evil or for good, have left imperishable monuments behind us. Such is the Athens for which these men, in the assertion of their resolve not to lose her, nobly fought and died; and well may every one of their survivors be ready to suffer in her cause (2.41).

A review of the origins and first moments of this war suggests that it was less a matter of growing fear and growing power, than a matter of tarnished honor and quests for glory. Athens’ growing wealth was a necessary condition for the war, but it was hardly the only or the most important cause of it. Had Athens’ quest for glory been less ambitious, had Sparta not tied herself to an ally hellbent on forcing her private wars and narrow interests onto the entire league of Spartan allies, and had the Greeks not been a people obsessed with insults, rank, and honor, this war may never have occurred. It was not an inevitable clash of fear and power that brought war to Hellas, but a very specific set of decisions made by a very specific set of leaders in the years before the war.

In some ways this is a heartening conclusion. The war was not inevitable—it was not the preordained result of some inhuman “Thucydides trap.” If this war was not inevitable then conflicts between the rising and settled powers of our day are not inevitable either.

 Not all of the implications of this conclusion are so heart-warming. The war between Athens and Sparta is misunderstood. It was not a war between a rising power and an existing hegemon. It was not, as is so often told, caused by a hegemon who failed to find a place for a growing newcomer in the existing order. That better describes the first war between Athens and Sparta. The war of Thucydides’ day was different. It was a war between two powers who had already reached a rough state of bipolar equilibrium. The Spartans had already accommodated the rise of Athens; at the end of their last war they had not torn down their walls, nor compelled them to give up their empire. Instead they had given the Athenians a secure place in the Greek world, a sphere of interests in which the Spartans agreed not to interfere. The lesson of the Peloponnesian War, may actually be the opposite of what many who invoke “Thucydides traps” intend! ‘Accommodating’ a rising power does not promise peace. The stability of such an accommodation depends very much on the nature of the power being accommodated.

What exactly prompted the Athenians to change tack in the 430s is hard to discern. Though the Athenians did not formally break the treaty, they instigated more than one “event… which [was] equivalent to a breach of the treaty and matter for war,” especially the decisions to embargo the Megarans and war against the Corinthians in defense of Corcyra (1.146). It is possible that the Athenians stumbled into these decisions unaware of their consequences. But if Athens was truly led by one man, and that man was half the leader that Thucydides claims he was, then this is unlikely. It is from the mouth of Pericles, not that of the Spartan war party, that we hear the claim that the war was inevitable. Pericles was quite clear about his priorities: what he sought was Athenian glory, glory to be remembered through the ages. He believed that Sparta would never let Athens seize such glory unmolested. Thus the Athenians were to persist in war, despite any peace offers received before it began or destruction wreaked upon their fields and homes afterwards. The Athenians could not reconcile their ambitions with Spartan hegemony—or even a rough and tacit parity. What tore apart Hellas, then, was not a hegemon caught in a Thucydidean trap of fear, but a polis whose quest for glory could not be sated by stable equilibrium.

Take from that what lessons you will.

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One Comment

I know this is an old post but as a french with a certain degree of familiarity with the history of my country and european politics, I must point out that this Belfer Center graphic is absolute nonsense.

European dynastic politics simply did not work that way. In no way could the Habsburg considered a "rising power" in the XVIth century Europe. They had been Holy Roman Emperors for more than a hundred years when Charles V united Spain with the old Habsburg domain in central Europe.

As for the idea that somehow in late XVIIIth century France was a "rising power", I am really scratching my head. France was THE dominant power in european politics from 1648 to 1815 or even 1870 (depends on how you see things). Its centrality explains why the french Revolutions of 1789 and 1848 had such a big impact. Nobody would have cared about a revolution in Naples.

Warfare in early modern Europe was practically constant, the Sun King did it for the glory and because he could, the british because their long-standing policy was to oppose the major power in the continent, the prussians because they wanted to survive and be recognized as a great power, the austrians because they were intent on trying to expand/preserve their power in Germany, etc. It's a massive oversimplification but it is still more complex than "Rising/Ruling".

What we don't need to understand european politics of the time is some kind of overblown historical metaphor. Whoever came up with this graphic has a poor understanding of european history or is willing to simplify it to a point where it becomes impossible to recognize.

This is why I distrut International Relations scholars, they like poorly understood historical analogies far too much for my taste.

End of rant, I love your blog. But this graphic really got on my nerve.