A result of the division of forces was the Peloponnesian's establishing a permanent garrison at Decelea in northern Attica. This was approximately fifteen miles from Athens itself. This forced the Athenians to give up the surrounding land and permanently live in the city. Thousands of slaves deserted to the Peloponnesians and industry and commerce shrank (Botsford and Robinson 218). This had a tremendous impact on Athens' economy and ability to finance the war.
With enemies at its back, Athens was unable to mass its forces in Sicily to conquer Syracuse. This hampered the expeditionjespecially in its lack of cavalry which Athens held back to defend Attica. Another failure was the Athenian utter disregard for operational security that greatly hampered the expedition.
During the Syracusan expedition the Athenian's lapses in security proved fatal to their campaign. A major error at the beginning of the campaign involved Alcibiades and the Athenian assembly's attempt to recall him. Immediately before the expedition's departure, the assembly suspected Alcibiades of religious sacrilege. Afraid of Alcibiades' power in the army, the Athenian assembly decided to wait until they departed to pursue the issue. The Athenian assembly indicted Alcibiades for sacrilege after he sailed for Sicily and ordered him to return to face charges.
On the return journey in a separate ship, Alcibiades escaped at Thurii and later went into exile in Sparta (218). The Athenians failed to anticipate Alcibiades' possible defection and take action to prevent it. A side consequence was that the assembly took the soul and tactical advantage out of the expedition by recalling Alcibiades. The expedition had a better chance of success if the command had gone to Alcibiades and Lamachus without Nicias (Bury and Meiggs 297).
While in exile in Sparta, Alcibiades turned traitor to Athens. While Athens was at war in Sicily, Alcibiades counseled the Peloponnesians on how to invade Athens. When the Peloponesians did invade, it disrupted Athens' industry, commerce and ability to further support the war in Sicily (218). His traitorous counsel would prove dangerous to his country's welfare.
Alcibiades started his revenge by informing the Syracusan party of the Athenian plot. The plot was to establish another foothold in Sicily by capturing Messana, a town in northern Sicily across from Rhegium. This betrayal resulted in the Athenian failure to capture Messana. His speech to the Spartan assembly was the turning point in the war. It shifted the balance of power at a critical time. He persuaded the Spartans to take part in the war and help Syracuse. He exposed the ambitious Athenian plans of conquest in the West. Once Athens conquered the West, it would enable them to return and conquer the Peloponesians.
Alcibiades knew the Syracusans lacked competent military leadership. He urged the Spartan assembly to send a general to Syracuse to organize its defenses. Alcibiades knew the importance of a...