How does the Melian dialogue of Thucydides reflect "realist" principles?
Thucydides' History of the Peloponnesian War is both a narrative of the events of the war and a political analysis of its causes and consequences. Throughout the History, Thucydides follows several strands of thought, examining how the actors on different sides of each confrontation are influenced by these ideas.
One such strand is the question of whether "might makes right," which is the central argument of the Melian Dialogue. The Athenians argue that it does and that, therefore, it is both natural and just that Melos should surrender to Athens. The Melians argue that "might" in this instance is opposed to what is morally right and that the Athenians should act in accordance with morality rather than expediency.
The Athenians begin by arguing that what is practical for them is moral for that very reason; furthermore, it is the natural order of things that "the powerful exact what they can, and the weak grant what they must." They state that, in light of this axiom, the Melians would do well to surrender. However, if the Melians are not convinced by the argument, the Athenians stand ready to convince them through superior force of arms. It is therefore in the Melians' best interest for Melos to surrender without a fight. This is a prime example of classical realism, which holds that all individuals and groups naturally prioritize their own interests over those of others. By demonstrating that surrender is the practical option, the Athenians believe they have proven that it is therefore the correct option.
The Melians challenge this notion and, according to Felix Martin Wassermann in his article "The Melian Dialogue" (linked below), "offer an impressive example that men fight and die not only for their interests, but for their beliefs, ideals, hopes, and even illusions."
The Athenians try to persuade the Melians with facts; the Melians counter-argue with ideals. The two sides are unable to come to an agreement, and the Athenians ultimately take Melos by force. Thucydides does not offer an opinion on the outcome but allows it to speak for itself: the Athenians may not have had the "moral high ground" here, but they did not need it to achieve their goal. From a realist viewpoint, they acted exactly as they should have to further their political interests, while the Melians acted against their own interests by clinging to their ideals.
Realism is a school of international relations that holds that states always act out of a desire to increase their security and their power. This is a school that does not concern itself with issues of the morality of state action. In essence, states should do whatever is necessary to increase their power and security because they exist in an anarchic order where there is no authority to protect them from the aggression of others. In the Melian Dialogue (part of Thucydides’ History of the Peloponnesian War), the Athenians say things that reflect realist ideas.
In general, the Athenians are saying that they have enough power to be able to tell the Melians what to do. They are saying that the Melians should give in because they are weak. They are saying that issues of morality are not important in this case.
For example, when the Melians ask about the equity of a certain course of action, the Athenians say
… if any maintain their independence it is because they are strong, and that if we do not molest them it is because we are afraid…
The Athenians also say that people will always “rule wherever they can” and that this is why the Athenians know that the Melians
and everybody else, having the same power as we have, would do the same as we do…
In these ways, this dialogue reflects the idea that states do what they are able to do to maintain power and security, regardless of issues of morality.
The Melian Dialogue is one of the earliest examples of realist theory. According to realist theory, the state does what is best for the state at the time. Political matters are neither moral nor amoral using this theory; it is best to do what is expedient. In the Melian Dialogue, the people of the island of Melos will not submit to the rule of Athens, which was the strongest Greek city-state at the time of the Peloponnesian War. The people of Melos argued that they should be allowed to chose their own destinies, but the Athenians argued that if they showed weakness toward the Melians the other small island states would also act defiantly. The Athenians took over the island of Melos not necessarily for its strategic value, but to send a message to other small states. While one could make the argument that morally Athens should not have done this—Melos was not hurting Athenian interests—according to realist theory, Athens was justified in doing this. The best way to maintain the security of the state is to display strength at all times.