Sanctions date back to antiquity, with the “Megarian Decree” issued by Athenian statesman Pericles in 432 BC being the first economic sanction recorded.
The Megarian Decree was an act of revenge by the Athenians for the treacherous behavior of the Megarians some years earlier.
However, if Athens openly attacked the Spartan ally it would violate the peace. Athens imposed the embargo to show other Spartan allies that Athens had other means of punishing attackers who were under Sparta’s military protection.
Thus, the decree could be seen as an attempt to avoid provoking Sparta directly.
Some historians argue that the Megarian Decree ultimately helped to prolong and intensify of the Peloponnesian War (431-404 BC).
Pericles imposes sanctions against Megara
Using the excuse of sacrilege against the land that was sacred to Demeter, known as the Hiera Orgas, Pericles wanted to punish Megara.
The supposed killing of the Athenian herald who was sent to Megara to reproach them, and their giving shelter to slaves who had fled from Athens, brought about the economic sanctions against the city.
The decree dictated that Megarian merchants would be excluded from the market of Athens and the ports in its empire, called the Delian League. The decree was something like a modern trade embargo.
If farmers had trespassed on sacred land, it was strange that the Megarian Decree aimed at punishing the merchants of the city. That implied a political aim.
Even though such sanctions were known and applied in the Near East, they had been unheard of in the Delian League.
Pericles was the first westerner to apply them, and for some historians that was the first time that economic sanctions had been used as foreign policy.
Sanctions as politics and the Peloponnesian War
In the late 430s, Athens and Corinth were on very bad terms. The Athenians had allied with Corcyra, a colony of Corinth, and in 433, the Corcyrans defeated a Corinthian navy, which included ships from Megara.
The Corinthians were members of the alliance of Sparta, the Peloponnesian League, and urged other members to fight Athens claiming that it was turning to a dangerous tyrannical superpower.
Athens could not attack Corinth, because that would immediately bring the Spartan army to the battlefield. Pericles chose to use diplomacy: The economic sanctions would be justifiable and not provoking.
Other than a blow to Megara itself, the Megarian Decree was also a warning to other city-states that those who supported Corinth would suffer as well. The economic sanctions were far from actual war, but would damage the potential enemy.
Pericles, who was friends with Spartan king Archidamus II, believed that the two powerful states would not go to war for the sake of a Corinthian-Athenian conflict.
The Athenian ruler was wrong, though. Not all Spartans were against war. On the contrary, most were in favor of it.
The historian Diodorus of Sicily, who uses Ephorus of Cyme as his source, wrote: “When the Athenians voted to exclude the Megarians from both their market and harbors, the Megarians turned to the Spartans for aid.”
The Spartans sent ambassadors demanding that Athens should rescind the action against the Megarians and threatened, if they did not accede, to wage war upon them together with their allies.
Pericles, with his great skill of oratory, persuaded the Athenians not to rescind the action, saying that for them to accede to the demands of the Spartans would be the first step toward slavery.
Thucydides confirms that the Spartan ultimatum was that there would be no war if the Athenians withdrew the Megarian Decree. This was a betrayal of Corinthian interests.
Diodorus wrote that the Athenians’ unwillingness to revoke the Megarian Decree was the direct cause of the war. It was as if the Spartans were ordering the Athenians to change their own foreign policy.
The Athenians found the Spartan ultimatum unacceptable. And that was a cause of war. On the other side, it was also a cause of war: Spartans would not let down their allies.
The failure of Pericles’ sanctions
For many historians, if indeed the sanctions dictated in the Megarian Decree had been used as a diplomatic move, then they turned out to be a failure.
Pericles believed that by sanctioning Megara, he could isolate Corinth. On the contrary, though, his move strengthened those members of the Spartan alliance that wanted war.
On his part, Archidamus made an error as well: He believed that he could ask for the revocation of the Megarian Decree after he had sacrificed Corinth.
Instread, he gave Pericles an opportunity to present the Spartan demands as unjustified, thus making most Athenians want to go to war.