Persian Intervention in the Ionian War, 413-404 BC

• In the spring of 413, possibly as the result of Alcibiades' advice (Thuc. 6.91.6), the Spartans invaded Attica under King Agis and occupied Decelea, a fortified outpost equidistant from Athens and Boeotia (Thuc.7.27): thus this phase of the Peloponnesian War (413-404 BC) is often referred to as the Ionian War

Change in Attitudes

The Spartans were convinced that the Athenians had clearly broken the terms of the Peace of Nicias, and that they were justified in renewing the war (7.18)

1. The Athenians' attacks on the east coast of Laconia in 414 BC (Thuc.6.105.2)
2. The constant raiding from Athenian-held Pylos (Thuc.7.18) and
3. The Athenian refusal to submit these issues to arbitration

This permanent occupation of Decelea caused many problems for the Athenians:

"It did great damage to the Athenians and, by its destruction of property and the loss of men, was one of the chief causes of the decline in Athenian power" - Thucydides 7.27.3

• The invasions in the Archidamian War had only been short affairs, the longest being forty days, but now the Athenians were permanently deprived of most of Attica:
1. the revenue from the silver mines was lost
2. 20,000 slaves escaped - the majority being skilled workmen and vital for the Athenian economy
3. the food supplies from Euboea had to be brought in by the more expensive sea route
4. there was the constant, exhausting guard-duty by day and night (Thuc.7.27-8)
• However, this stand of Spartan strategy, for all its debilitating effects on the Athenians, was insufficient to win the war as King Agis of Sparta so astutely observed as late as 410 BC
• "Agis, seeing from Decelea many corn ships sailing into the Piraeus, said that it was useless for his troops to cut off the Athenians from their land, which had been done for some time now, unless some one were to seize the places from where the grain kept coming in by sea" - Xenophon, Hellenica 1.1.35
• The Spartans had to be far more adventurous and challenge the Athenians at sea in Ionia, and especially in the Hellespont

Key Fact

Only by breaking up the Athenians' sea empire, on which they depended for revenue, and by preventing corn from the Hellespont reaching the beleaguered Athenians could the Spartans win the war

• The destruction of the Athenian fleet in Sicily in 413, however, had fulfilled one of the two pre-conditions for potential Spartan success in Ionia; the other - sufficient finance to pay the crews of a fleet that was large enough to wrest power from the Athenians in the Aegean - required the full involvement of the one power that had the wealth and the desire to destroy the Athenian Empire: Persia
• Persia's financial help to the Spartans, fitful at first but more committed later, gave the Spartans the means to wage war with the Athenians in Ionia: hence 'Ionian War' being the alternative name for the war from 413-404 BC. However, it is essential to see how the Persians were gradually drawn into the Peloponnesian War from the beginning and why the King of Persia chose to support the Spartans in the Ionian War