More Athenian aggression follows, directed unequivocally against…

More Athenian aggression follows, directed unequivocally against other Greeks: Carystus, at the southeastern end of Euboea, is forced to join the league.

Athenian involvement in Euboea goes back to the sixth century, when Athens had installed a cleruchy on Chalcis soon after the Cleisthenic reforms.

Thus, the Delian League, an association of Greek city-states, comes under the military leadership of the Athenians.

The justification for this is that Carystus had been enjoying the advantages of the League (protection from pirates and the Persians) without taking on any of the responsibilities.

Furthermore, Carystus, having been subjugated by Darius in 490, has been a traditional base for Persian occupations.

The Athenians, professing outrage at this recalcitrance, attack Carystus and torch the entire city.

This tactic is a strong deterrent to any Greek city-state inclined to side with Persia and offer their city as a base or simply to enjoy the advantages of a Persian-free Greece without paying their share.

Athenian politicians have to justify these acts to Athenian voters in order to get votes.