Once Cyrus conquered Croesus and the Lydians, some of Croesus’s neighbors tried to surrender.  “We totes want in on the sweet sweet vassalage setup Croesus is rocking,” they said.  “Still alive, acting as Cyrus’s advisor, the population treated well and not ruinously taxed!  That’s the life for us!”

Cyrus’s response was to compose an elaborate fairy tale about a magic flute and fish and nets and when you played the flute the fish danced and jumped in the nets, except that the fish refused to dance until there was a bad storm and then they fish were all “ooh Cyrus let us become your vassals!” and the long and the short of it was that Cyrus didn’t like fair-weather vassalage.

Herodotus realizes you seem confused by this anecdote.  He forgot to mention it before but before Cyrus launched his counter-invasion of Lydia, he offered to accept the surrenders of these neighboring countries, and they refused.  That puts Cyrus’s story in a little bit more perspective.

When they heard that Cyrus wasn’t accepting their gracious surrenders, the Ionian neighbors (Herodotus lists a bunch of cities but they aren’t important) embarked on a crash wall-building campaign and sent word to the Spartans begging for assistance.  Herodotus at this point tries to sum up Hellenic intracultural politics, that is, the various city-states, and he goes on for quite a while with a lot of place names and names for ethnicities which don’t come up again.  The upshot is as follows.

1. The Greeks in general were super divided, along regional and subcultural lines.
2. Two of these subcultural regions were threatened by Cyrus, the Ionians and the Aiolians.  They weren’t in what we think of as Greece itself, but were actually two region in modern-day Turkey, on the coast across the sea.
3. All Ionian the city-states threatened by Cyrus were kind of pissant losers.  But to be fair, among the Greeks of back then, only Athens wasn’t a total loser pissant city-state.
4. There the Panionion, which was a small league made up of a dozen Ionian city-states, and they hosted a festival called the Panionia.  This isn’t important; I just think it’s adorable.
5. The Aiolian city-states were less awesome than the Ionian ones, but their land was more fertile and there were more of them.  Ionia was all rocky and lame, while Aiolia was green and verdant and included some great islands like Lesbos.

Herodotus has a lot more to say, but we’ll skip it as boring.  So, the Spartans!  The Aiolian and Ionian messengers met outside Sparta, where they compared notes.  They needed to put together a really high-end presentation and get the Spartans moving quickly; Croesus had tried to recruit them and they’d agreed, but then they were busy with some religious festival bull hockey and wouldn’t come right away.

“Help us, Spartans!” cried the messengers’ main spokesman, a guy in a purple cloak named Pythermos.  He had a whole song-and-dance set up; the messengers had pooled all of their resources and spent all their cash on prettying up Pythermos and hiring him a dialogue coach and running practice debates and private push-polling and all the traditional democratic methods.

But the Spartans would have none of it!  “Screw you!” They didn’t consider Athenians and their Ionian lackeys to be worth the time of day.  “Good day!”

“B, but…!”

“I said good day!”  And the Spartans slammed their doors in the Pythermos’s face.

While the messengers returned home with their heads bowed and their tails between their legs and sad music playing, the Spartans reconsidered.  Just because the Ionians were dips didn’t mean that this Cyrus fellow wasn’t a threat.  After all, Croesus had folded like a napkin.  So they sent a single boat out to Sardis, to reconnoiter and diplomatize with Cyrus.