Preparing for Peace? Lessons from Antiquity in an Uncertain Europe

For decades, many Europeans took peace and security for granted. However, recent geopolitical developments have reminded us that peace, besides being precious, is also deeply precarious. The threats of war are no longer confined to distant continents—or even to Europe's borders. Massive new investments in military defense reflect a worrying reality, while the old Latin adage si vis pacem, para bellum— "if you want peace, prepare for war"—is once again being taken literally and seen as an essential principle.

In a way, the dilemmas of our time and recent disenchantments seem to mirror ideas already debated by authors from the early centuries of the Roman Empire. This era, so often idealized by its Pax Romana , began when the first emperor, Augustus, emerged victorious from the civil wars that had torn the Roman Republic apart, defeating Mark Antony and Cleopatra at Actium in 31 BC. From then on, he proclaimed a new era of stability and prosperity. This "peace," which lasted for two centuries until the death of Marcus Aurelius in 180 AD, was widely celebrated throughout the empire—even as the Roman legions continued to wage war on its borders, from North to South and from West to East. The illusion of lasting peace thus concealed latent tensions.

Intellectuals of the time frequently reflected on the concept of Pax Romana , and many extolled this seemingly blessed state in their literary works. But this praise did not mean they ignored its contradictions. On the contrary, they seriously questioned what peace truly was and how it could be preserved for future generations. One of the main resources of this pacifist discourse was the use of exempla : stories of illustrious figures from the past, intended to instruct readers on the complexity of human behavior, highlighting both virtues and vices.

Sometimes, these authors addressed the emperors themselves directly, attempting to influence their decisions and guide them toward preserving this fragile peace. The Greek philosopher and biographer Plutarch of Chaeronea, for example, collected around five hundred anecdotes in the work "Sayings of Kings and Generals ," dedicated to Emperor Trajan around 117 AD, the last year of his expansionist reign. Recent analyses suggest that, through these exempla , Plutarch sought to encourage the emperor to prioritize the empire's internal stability, following the example of the "peacemaker" Augustus.

Irony of fate: many of the heroes portrayed by Plutarch and his contemporaries actively participated in wars, often as commanders. This is not surprising, since conflicts tend to be the stage for extraordinary actions and complex ethical dilemmas. However, the bloody dynamics of the Greco-Roman past taught the writers of the first and second centuries that the dream of a perpetual Pax Romana could itself be an illusion. Peace should not be taken for granted. The fact that they repeatedly revisited the horrors and traumas of previous generations reveals a deep awareness of their fragility.

Today, faced with a new wave of insecurity, the classical tradition offers us neither straightforward answers nor easy solutions. But it reminds us that peace requires continuous effort and the courage to learn from the past. Just as Roman intellectuals sought to shape their future by reflecting on previous conflicts, we too must continue to revisit history—not to glorify war, but to postpone, prevent, or mitigate what may sometimes seem inevitable.

Laurens van der Wiel, postdoctoral researcher at the University of Warsaw, and Wim Nijs, postdoctoral researcher at the University of Toronto and speakers at the Celtic Conference in Classics