Thucydides found the reasons for war, first among all schools of international relations. But besides addressing the causes of war, Thucydides also explored some other vital issues that deal directly with international relations theory, even nowadays.
First, he addressed the question of morals and international politics. He was explaining, addressing, and studying the question of morals in international politics through the example of the collision between Athens and the small island Melos, which is led by its party union.
Athens invaded Melos back in 416 BC and demanded that Melians, the people who lived there, surrender and pay tribute to Athens and join their alliance or face destruction. The Melians refused, and after the siege, the Athenians captured the city and slaughtered most of the population.
The Melian Dialogue, the negotiations between the two sides before the battle, which we can find in the book of Thucydides, represents one of the most ancient icons of morals and power in international politics.
Melian dialogue is a discussion between the delegations of Athens and Melos. People from Athens insist on their right to do what they want and demand that Melos surrender. People from Melos said they would not go to fight against Athens, they wanted to keep certain neutrality, but the Athenians were very, very persistent.
An Athenian perspective on morals is the following, the Athenians say, right as the world goes, only in question between equals and power, while the strong do what they can, and the weak suffer what they must.
So, we see that according to the classical religious tradition’s first statement, their morals, their right, and justice can exist only between equals and power. But when we deal with the relationship between stronger and weak countries, according to the realist tradition, we no longer speak about justice and morals.
According to Thucydides, the standards of justice depend on the equality of power. We will find the same ideas in many works of scholars who belong to the realist tradition even much later. For example, we found the same concept in Edward Hallett Carr’s works, which were written back in 1939.
Edward Hallett Carr writes that morality and politics are not derived from the normal morality of the relationship between people; the morality in politics is a very special morality that is typical only for this exceptional relationship. But after the most remarkable findings of Thucydides, the classical tradition experienced its decline.
The Decline of Classical Tradition has several reasons, which are stated below.
The first and most important reason was the rise of the roman empire which brought universal state civilization, Pax Romana.
The Roman empire developed from a tiny republic on the West Coast of the Italian Peninsula to a vast empire that embarrassed all of contemporary Europe, North Africa, and the Middle East, stretched from the British islands to Palestine and from Morocco to the German forests.
It was a superpower for that period. Another superpower was the Chinese empire in the east. But those two countries have never interacted, and history doesn’t have any experience of the relationships between the two first superpowers. Pax Romana did not leave a place for the balance of power concept, as there were no other states to challenge their own. Relationships with Barbarians and the Romans called everybody who surrounded them; BarbariansThe Romans never considered barbarians as an interaction of equals.
It was an eternal war between the civilized world and the uncivilized periphery. What made the Romans view this relationship as a moral conflict between the two societies where one had a more advanced domestic order while the second put a threat to it? The same situation we find in the east, where the Chinese Empire has never considered its neighbors as equals, is why the theory of international relations has never developed in China.
Today, our Chinese colleagues need to accept the international relations theory developed in Europe, where other nations experienced relationships between equals after the Roman Empire collapsed for many centuries.
The other reason for the decline of the classical tradition was the emergence of Christian Universalism. After the Roman empire collapsed, a new idea came from the Middle East, the Christian religion. It emerged and dominated Europe till the sixteenth and seventeenth centuries.
Christianity suggested a new idealistic interpretation of history, which hardly correlated with tradition.
While Thucydides considered the international system static, Christian doctrine viewed history as a permanent transformation from one condition to another. The final destination of mankind is the End of History, the Kingdom of Heaven.
The return of classical tradition appeared only at the end of the fifteenth and beginning of the sixteenth century. Renaissance returned to the tradition of international relations at the center of intellectual life. It was partly driven by the emerging interest in the Ancient legacy of Literature and philosophy.
However, the Renaissance became a birthtime for the first centralized states, which formed the first post-feudal balance of power in Europe and especially, in the Eponym peninsula, during the Italian Wars of 1494 to 1559.
At the end of the fifteenth century and the beginning of the sixteenth century, the first states emerged, and those states treated each other as equals, and that’s why they needed again ideas about how to treat each other.
The thinkers of that age developed a new general approach to the theory of international relations, and one of the most essential authors here is Niccolo Machiavelli.