Allies, Adversaries, and Illusions: The Enduring Lessons of Thucydides

For thousands of years scholars and policymakers alike have drawn on the wisdom found in Thucydides’ canonical text, The History of the Peloponnesian War. Most frequently they have relied on familiar phrases, oft-repeated, as solemn lessons from the past. Though frequently misquoted, void of critical context, or completely fabricated, readers have found comfort in using these quotations to validate their existing opinions with the endorsement of an ancient scholar.

But while we and many other authors have focused attention on the problem of recycling familiar admonitions from the past, there are other, broader lessons to be drawn from Thucydides which are woven throughout the book rather than compressed into one or two lofty paragraphs. Perhaps foremost among these are examples of the perception of power and the perils of alliances. Thucydides gives us complex accounts of how the formation, application, and even the collapse of alliances all require the careful attention of academics as well as political leaders.

Thucydides initially introduces this challenge in recounting the formation of the Delian League. That seemingly straightforward agreement to organise resistance against Persia, structured military cooperation, defence initiatives, finance, and the allocation of the spoils of war. Ultimately it evolved into one of the first breaks in trust and cooperation between Athens and other nations. Athens’ dominance of the League created fears in Sparta. Athens demonstrated ability for dynamic growth, the extraction of financial benefit from its friends, and the ability to challenge Sparta’s allies. In a quarter of a century, a coalition created to prosecute the war against Persia became an Athenian empire, dominated by Athens, for the primary benefit of Athens. Alliances, as Thucydides reminds us, are not fixed and immutable. Commitments to alliances are highly dependent on the interests of the actors involved, whether those interests are accurately understood or dangerously misperceived.

Next, Thucydides provides us multiple examples of how seemingly weaker states can leverage unique or asymmetrical capabilities and resources, in ways that draw larger nations into dangerous and unmanageable conflicts. Trusting in a conventional assessment of their power, and inattentive to rich contextual details that shape the actions of smaller states, Athens and Sparta were again and again drawn into clashes that would have been better left avoided. The Peloponnesian War itself, in Thucydides’ account, begins because of the pressure of Corinth on Sparta to not abandon its allies. Athens launches the destructive expedition against Syracuse on the excuse of protecting its allies in Segesta.

The logic of entrapment works not only against large states drawn into conflict to protect their smaller proteges but for small states who believe too much in the security guarantees of their patrons. Such logic is present in the famous episode of Melos. Here, the small island of Melos resists Athens in the belief that Sparta may come to its aid. Abandonment, not entrapment, was the result, and Melos was destroyed. Melos’ miscalculation is the obverse on the coin of an Athenian miscalculation. It is an example of how the strength and longevity of alliances can also be misread by other nations not a party to that agreement. Melos had hoped that its neutrality would protect it. But in the mind of Athens, Melos was an important strategic asset of Sparta, and Athens has several sound reasons for that conclusion. In hoping for Spartan aid, and the possibility of entrapping Sparta into renewing its war with Athens, Melos tied itself to an alliance that was no longer a guarantee of safety but rather an invitation to outside aggression.

Finally, perhaps the most significant, overarching example of alliance risks and fragility lies in the fact that these now-mortal enemies – Athens and Spartan – had been staunch allies only a generation before. When Persia threatened all of Greece, Athens and Sparta were firmly united in the face of that invasion. The Athenians at Marathon and Salamis and the Spartans at Thermopylae and Plataea sacrificed for the security and survival of all the Greeks who refused to submit to Persia. A generation later, they were engaged in a prolonged series of wars that would ultimately destroy and submerge both nations for almost 2,000 years.

Alliances are important tools in any statesman’s arsenal. If wisely managed, nurtured, and viewed for their strategic value rather than for any temporary tactical advantage or cost, alliances can be the most effective, sustainable, and economic means for state security. Ignoring or short-changing the maintenance of alliances, failing to carefully track their evolution, or tethering oneself to an alliance long past its utility are serious risks, evidenced in the writing of Thucydides, and in many, many other examples found in the centuries since.

Disclaimer: Views expressed are of the author(s) and do not necessarily reflect the views of The Statecraft Institute.