How does the author use foreshadowing in Tides of War: A Novel of Alcibiades and the Peloponnesian War?

In Book VI, Endius' realization that Lysander matches Alcibiades foreshadows future events. As Alcibiades is the central figure of the Peloponnesian War and the ultimate downfall of Athens, Lysander is the central actor in the downfall of Alcibiades.