Good strategy requires a sound understanding of one’s rivals. A rival in any walk of life is, in a sense, an interlocutor. To engage him effectively in debate one must understand his speech and reasoning patterns. Without that knowledge, conversation is at best pointless, at worst self-defeating. So it is in strategy. It is futile to engage in competition with a rival power without having at least an inkling about his thoughts, fears, and desires.

The modern Western penchant for trusting in the equal rationality of all suggests otherwise. According to this conceit, there is no reason to plumb the nature of an enemy’s thinking because it is no different in essence from one’s own. But this is wrong. A rival’s response to one’s strategy is not predictable as a simply rational and universal reaction that can be generalized and grasped with relative ease. Rival states or groups respond to similar actions in different ways based on their culture, worldview, history, and the proclivities of their leaders. Good strategy, as Bernard Brodie once put it, “presupposes good anthropology and good sociology.”

One of the earliest examples we have of “good anthropology”—or rather, of being able to put oneself in the mind of the enemy—is in a 5^th-century BCE Greek tragedy, The Persians, written by Aeschylus. (The translation used here is from the 2008 Loeb edition.) This drama recounts the moment when the Persian court and queen learn of Emperor Xerxes’s defeat by the Greeks in the 480 BCE naval battle near Salamis. (For an excellent description and analysis of the battle, see Barry Strauss’s The Battle of Salamis.) It ends with the arrival of the Persian king himself, in rags and with few men left, lamenting his enormous loss “in triple banks of oars”—a reference to the fearsome Greek triremes. The genius of the tragedy resides in part from the fact that it is told from the Persian perspective, with no Greek characters present. It thus stands as a Greek assessment of the Persian enemy’s mindset and political regime, and a brilliant one at that.

The Greeks defeated the Persians because of Aeschylus. I do not mean, of course, that Aeschylus alone clobbered the “barbarians” coming from the east. But he was certainly an active participant in the wars that pitted the vast and wealthy Persian empire against a collection of motley Greek city-states. He fought at Marathon in 490 BCE as a foot soldier opposing the armies of Darius I. The battle stopped the Persian onslaught in a lopsided victory for the Athenians (according to Herodotus, about 200 Athenians, among then Aeschylus’ brother, were killed while more than 6,000 Persians perished). As a middle aged and by then famous poet, Aeschylus is also likely to have fought at Salamis, probably waiting on shore to finish off Persian sailors seeking safety from their sunken ships.

Aeschylus’s material contributions to the war effort were likely on par with those of thousands of other Greeks. But his real martial input was different. In The Persians he shows a unique ability to put himself inside the Persian court, describing the wishes and fears of those powerful eastern “barbarians”, as well as sensing the dangers that arose for them from their defeat in Greece. Besides the haunting beauty of the tragedy, The Persians is an exercise in playing “red team”, assessing the enemy from one’s own perspective and surmising what is impossible to know for certain even with the best intelligence: the fears and dreams, the despair and hope, of the rival.

After all, an appraisal of material capabilities can only quantify the tangible assets of an enemy, but not his mind. No high-level spy or communication intercept can figure out an enemy’s thinking either; “signals intelligence” is always vulnerable to distortion and manipulation. Even when trustworthy it requires proper interpretation and analysis. It is not surprising, therefore, that we often fall back on measuring the enemy’s armies, economies, and populations as indicators of what he may achieve. In such an assessment of material variables, the implicit logic is: If the enemy can, he will; and if he cannot, he won’t. In modern academic parlance, we use capabilities as proxies of intentions.

This is a weak foundation to rest upon nowadays, as it was 2,500 years ago. The Persians did exactly that with the Greeks, and they lost. As the messenger bringing the bad news of the defeat to the Persian court puts it, “so far as numbers are concerned, the fleet of the barbarians would have prevailed.” As we know, despite their calculations, the barbarians did not prevail. On the other hand, Aeschylus indicates that the Greeks, or at least some Greeks such as the Athenian leader Themistocles, evaluated their enemies according to different metrics and, above all, were capable of understanding the Persian mindset. The Greek advantage was not material but intellectual.

The proof that the Greeks had assessed the Persians better than the other way around was the Battle of Salamis itself. Obviously, the outcome was a stunning Greek success, but a martial victory can be attributed to a whole host of reasons, including luck, rather than exclusively to a better anthropological understanding of the enemy. It is the Greeks’ deception of Xerxes before the battle that shows their intellectual advantage over him. As Aeschylus recounts through the words of the Persian messenger who arrived at court, the night before the battle a Greek from the Athenian fleet came to the Persian camp and said that the Greeks would try to escape with their ships before dawn. Both Herodotus and later on Plutarch recount a similar story. Herodotus adds that the Greek messenger was Sicinnus, a slave of the Athenian leader Themistocles, sent to deceive the Persians but also, by encouraging the Persian fleet to surround the Greek ships, to commit the multilateral and perhaps fraying alliance of the Greeks to battle.

In any case, the Greek deception of their enemy succeeded because Xerxes, and perhaps the Persians in general, thought that an alliance of semi-equals, such as the one the Greek city states put together, had little chance of maintaining unity in the face of Persian might. The Persians ruled over their subordinate groups, while the Greeks had to negotiate with each other. Xerxes naturally thought that his way of diplomatic management, based on autocratic rule, was superior, and so he was easily convinced by Sicinnus that the Greeks were a motley rabble of competing cities, eager to save their own skin at the expense of their neighbors. After all, he knew that without the iron fist of Persian power the Egyptian, Ionian, and Phoenician contingents would perhaps have withdrawn to their own lands. The Ionians had revolted a few years before, supported in part by Greek cities. Xerxes, projecting these thoughts to the other side, thought a similar dynamic must have been at work in the Greek coalition, which lacked the god-like rule of an emperor. Autocrats typically doubt that unity is possible without the fear of imperial command.

Confident that the Greeks were indeed trying to escape, Xerxes ordered his fleet to enter the straits near Salamis. The Persians spent the night awake and alert, eager to attack those among the Greeks who were expected to try to run away under cover of night. Dawn found the Persians tired and shocked at the sight of the Greeks ready to fight them in an environment that minimized the numerical advantage of the barbarian fleet. The Persians had been fooled and suffered a massive naval defeat.

No wonder that in The Persians Aeschylus has a poor opinion of Xerxes. Themistocles was able to deceive Xerxes because the latter massively misjudged the Greeks. Themistocles instead understood perfectly the mentality of the Persian, and put it to good use. The Persian emperor was guilty of having committed both a strategic and a tactical mistake that cost him dearly – and both mistakes stemmed from his poor assessment of the enemy. The strategic mistake was to invade Greece in the first place. To make that point, the Greek poet evokes the ghost of Darius I, Xerxes’s father. Darius had suffered his share of defeats, notably in the plain of Marathon. From that disaster he learned that the Greeks appeared divided, weak, and poor but when pushed to the brink were capable of great feats of military valor and political acumen. It was better to let them be. Moreover, when invaded by a large army, Greece fought back “by starving to death a multitude that is too vastly numerous.” Living off the land was not feasible for an enormous army in a relatively confined space of the Greek peninsula. Xerxes, however, was too arrogant to understand this and was eager to demonstrate that he was more than a “stay-at-home warrior” (in the words of his mother, the queen).

This larger mistake was compounded by the tactical error, a result of Greek deception, to fight a battle at sea under conditions that favored the well-trained Athenian fleet. As the Chorus of the Persian court puts it, “Xerxes handled everything unwisely, he and his sea-boats.”

Aeschylus possessed two additional insights into the Persian mindset. First, he suggests that an autocratic regime, such as the one headed by Xerxes, has limited accountability. This influences its strategy. As the queen mother argues while waiting for news, were her son Xerxes to succeed, “he would be a very much admired man, but were he to fail—well, he is not accountable to the community, and if he comes home safe he remains ruler of this land.” An emperor is the author of victories, but not of defeats, attributed to the meddling of antagonistic gods or the poor performance of incompetent subordinates. Of course, once the news of the rout arrives, neither she nor the ghost of her husband Darius can fully exonerate Xerxes. But Aeschylus has already made the point: Autocrats and despots take risks that leaders accountable to their populations, or even to an elite class, would not. Despots are dangerous because they are unmoored from political constraints, and their advisers are often sycophantic courtiers rather than wise counselors. Perhaps more importantly, the costs of defeat are borne by imperial subjects, as the long list of Persian names presented by Aeschylus (49 in total) shows, not the emperor himself.

The defeated autocrat will, of course, be distraught. The ending of The Persians is a powerful and quick back-and-forth between Xerxes and the Chorus, full of wailing and despairing. But there is little self-examination. The more levelheaded analysis is rather done by Darius’s ghost, who returns to the underground before the arrival of the bedraggled Xerxes. Xerxes can only muster despondency in the face of the fact that he has lost so many of his “defenders” and “escorts.” (The Chorus adds that they were also “friends”, but Xerxes may have understood better that emperors have few friends!) Despair is an act of emoting, not of analysis; nor does it admit of unfulfilled responsibility.

The second insight of Aeschylus concerns the nature of imperial fears. The Persian Empire did not collapse after Salamis; indeed, it outlived Athenian democracy and the relatively brief harmony that the Greeks managed to achieve in facing the barbarian onslaught. But Aeschylus points out that the power of Persia, or for that matter of any empire, was as much in its image of power as in its material capabilities—and that image had been damaged at Salamis. The Chorus observes that after the defeat one ought to expect a fraying of imperial ties.

The weak spot of a despotic regime or an empire is that it is held together by whatever reservoir of fear it can muster. That fear is a mindset generated by an expectation of retribution rather than by the constant application of power against rebellious subjects. Such an expectation will understandably decrease when imperial forces have taken a hit in some corner of the empire, however distant. That is why the Persian Chorus can claim that the island of Salamis “holds the power of Persia in its blood-soaked soil.”

Aeschylus’s prediction—or, more precisely, the despair of the Persian Chorus—that Persia would fall apart did not come true, even though various regions under Persian rule did rebel. On the contrary, it was Greece that became more divided after the Persian Wars, particularly in the form of a long and bloody war between Athens and Sparta. But Aeschylus was not forecasting history; he was describing the worries of the imperial court and the fears of the Persian enemy. Whether those fears came to be exactly as imagined or not is in many ways irrelevant because people often act on the basis of such fears. Understanding their fears is therefore more important than figuring out whether they are justified. In this case, Aeschylus suggests that a despotic regime is always attuned to its survival and, when defeated, is likely to focus inward to assuage that fear. This may be also a veiled justification for why the Greeks chose not to purse the defeated armies of Xerxes, lest the Persians turned back in a moment of courage out of despair. Pushed too hard, their fear of internal collapse resulting from the loss of reputation may have forced the Persians to remain in Greece.

But it also suggests that the best way to keep the Persians in check was to stoke rebellion within their empire, as the Greeks had done to a degree with the Ionians and later on would do with the Egyptians. The strategic advice implied by Aeschylus was that, unless forced by a hostile army invading their lands, the Greek cities were better off not seeking a direct confrontation with a powerful empire like Persia, but should stoke Persia’s fears that its imperial subordinates may “no longer keep their tongue under guard.”

Aeschylus is not a triumphalist. He does not shy from celebrating, albeit briefly, the Greeks who were eager to fight because their freedom was at stake. They were, after all, “not called slaves or subjects to any man” as the Persians admit. And the Greeks at Salamis fought as one, defending together their liberty from barbarian oppression. (Interestingly, Aeschylus names no individual Greeks, suggesting perhaps that naval victories were products of a well-ordered fleet rather than of individual exploits. A naval defeat results in many individuals dead, with a list of Persians killed, but a naval victory has no hero, with no Greek celebrated.) But, despite this recognition of martial and political superiority, there is little triumphalism in the tragedy.

What is surprising is that, with poetic license but sine ira et studio, he generates enormous sympathy for the Persians. Aeschylus, a member of the victorious army, can summon an astounding capacity to pity the defeated enemy—an enemy that also almost two decades before the production of the tragedy caused the death of his own brother in the fields of Marathon. That capacity to put himself on the Persian side, to imagine and intuit rather than to touch and calculate the deepest emotions of the enemy, is not a symptom of relativism. Nor, as modern academics so often do, is it something to be criticized as a denigration of the “Oriental Other”, full of stereotypes and negative traits ascribed to the “barbarians.” Aeschylus with his Persians is an exemplar of the Greek intellectual capacity to understand their enemy in ways that transcended a simple calculation of the “correlation of forces.” That is what gave the Greeks an advantage. They won because of Aeschylus; that is, they won because of their ability to understand the Persian court and emperor. They beat their enemy’s mind before they engaged his forces.

Another way to put this is that a great power risks defeat when it lacks figures like Aeschylus, poets who can feel the enemy before they face him in battle. Competition and war are not driven by mathematical equations but are a clash of minds and wills, fears and desires, often only loosely connected to the material capabilities at hand. In the geopolitical competitions that we are facing and are likely to face in the future, do we have our own Aeschyluses?