Perhaps without realizing it, Americans know firsthand the lesson about ethics, democracy, and war that Thucydides teaches his readers in his History of the Peloponnesian War. Thucydides’ lesson is this: when a technologically-advanced democracy has great power it can find itself frequently engaged in conflict. And when it does, the war can be very, very long. In agrarian societies, there is a season for war, because agrarians must be home for planting and harvesting. The Athenians knew what we Americans now know: for empires, every season is a season for war, because empires can afford to divide their labor and devote great resources to the deployment of troops.
The Peloponnesian War, like most wars, can be traced to political tensions that arose well before any fighting broke out. Thucydides explains that the war was caused by “the growth in power of Athens, and the alarm which this inspired in Sparta.” This is not wholly accurate: Athens’ unipolar moment inspired alarm not just in Sparta but in all of the Greek city states that fell in behind Sparta as the confrontation got under way. In the preceding years, Athens had emerged as the sole superpower after successfully defending the better part of Greece from the Persians, who had threatened to take over the ancient world. With the Persians out of the way, the task of governing the empire was left to the Athenians—who were happy to do it.
This would be no ordinary empire, however. Athens was the democratic and cultural center of the Mediterranean region and, according to Thucydides, became an empire through the permission of its neighboring city-states. The Athenians argued, perhaps rightfully, that they “had done nothing extraordinary, nothing contrary to human nature in accepting an empire when it was offered to us and then in refusing to give it up.” The Athenians may not have been doing anything contrary to human nature, but their actions were contrary to the hopes and ambitions of Sparta and its allies. This became clear in a nasty little confrontation between Athens and Samos, a small but rather powerful city state.
In 440 BCE, the Samian oligarchs agreed to go to war against Miletus, one of the few democracies in the region. It is unclear whether Athens came to the assistance of the Milesians for the sake of defending democracy or for the sake of economic and political power. With the help of a transformational piece of military technology, the Athenians squashed the Samian force. Athenians possessed a major technological edge, a vessel known as the trireme. The trireme was the cruise missile of ancient warfare: fast, light, and powerful, triremes allowed Athens to project power across the eastern Mediterranean—especially since, for a time, Athens was the sole proprietor of this technology. Forty of these vessels could be launched from an Athenian port to quickly lay siege or blockade coastal towns like Samos around the Mediterranean. The Samian War lasted a little less than nine months, the approximate length of the First Gulf War. And like that U.S. military campaign, the Samian War was initially regarded as an unadulterated success by the victors: Athens’ objectives were accomplished and very few casualties were taken, thanks to the technological superiority it enjoyed. Thucydides, however, suggests that the real costs and consequences of such victories often take some time to become apparent—even, and perhaps especially, when the victors are inclined to overlook them.
The Samian War, like Operation Desert Shield, polarized the international community. Sparta and Corinth did not support the Athenian intervention, but welcomed the chance to see the Athenian military in action, garnering valuable information that would inform their strategy in the Peloponnesian Wars. One thing was starkly obvious to them: they could not beat the Athenians at sea—at least not yet. The coming conflict, therefore, would be fought in two different spheres of combat; Athens would control the sea, Sparta the land. What the Spartans lacked in technological sophistication, they made up for in manpower and blind dedication to the cause. The Spartan foot solider, or hoplite, was unrivaled on the battlefield. The Athenians recognized this fact: they, along with the rest of the ancient world, knew what happened at Thermopylae in 480 BCE when three hundred Spartans effectively held off a much larger Persian army. What was unsettling (at least for the Athenians) about Thermopylae was that a few Spartan warriors had been willing to die in a hopeless battle, if only to make the Persians suffer in the process. This should sound familiar to us.
In the face of such a ruthless foe, Athens did what many wealthy democracies might do: it built a wall around itself. Some of the walls of the Peloponnesian War are still visible in Athens, hastily built out of whatever the ancient Athenians could lay hands on. It’s an interesting feature of Athens that a number of walls contain other building materials—the remnants of roofs and doorposts—suggesting that some buildings were torn down to make the walls. This is instructive, if not cautionary: in our attempt to protect ourselves, we often destroy the very things that we long to protect.
As fighting between Sparta and Athens broke out in the 450s, Athens began the construction of two long walls, creating a fortified corridor between Athens and its seaport at Piraeus. The Long Walls were erected in order to provide refuge to the Athenians who abandoned the countryside of Attica as the Spartans invaded. The walls connected landlocked Athens with one of the nearby harbors, allowing resupply and, if necessary, a means of escape. The reliance on this safe haven was not viewed as a point of weakness, but, on the contrary, was understood as a strategic advantage by Athenian leaders such as Pericles. Thucydides also defends this strategy by arguing, “Suppose we were an island, would we not be absolutely secure from attack? As it is, we must think of ourselves as islanders.”
As we look back across the centuries, it is hard not to admire the greatness of Athens at its height. For a brief Golden Age, it flourished and gave us much of the culture we cherish today. We owe the ancient Greeks, and the Athenians in particular, a great debt of gratitude for giving us the beginnings of democracy, philosophy, our performing arts, our sciences, and our system of education—and so much more besides.
And we owe them gratitude for their cautionary example as well. Athens’ history reminds us that military power and technological advancement do not guarantee safety or perpetual prosperity. It reminds us that as our power increases, so do our opportunities for conflict. It reminds us that it is all too easy to recklessly safeguard our wealth and comfort at great expense to our neighbors, and to unintentionally engender great fear and resentment as we do so. As we dwell in our golden, Athenian age of military and economic might, perhaps we should learn another lesson from the ancients as well. Aristotle tells us that a virtuous soul is not a soul without fear, but one that fears only the right things; and it is not moved by fear, because it tempers it with wisdom. In the end, the loss of virtue may be more dire than the loss of geopolitical prominence.