Excerpts from Books and Wikipedia
"The Corinthian War was an ancient Greek conflict lasting from 395 BC until 387 BC, pitting Sparta against a coalition of four allied states, Thebes, Athens, Corinth, and Argos, backed by the Achaemenid Empire. The immediate cause of the war was a local conflict in northwest Greece in which both Thebes and Sparta intervened. The deeper cause was hostility towards Sparta, provoked by that city's "expansionism in Asia Minor, central and northern Greece and even the west.". . . Alarmed by these Athenian successes towards the end of the conflict, the Persians stopped backing the allies and began supporting Sparta. This defection forced the allies to seek peace. . . . This treaty declared that Persia would control all of Ionia, and proclaimed that all other Greek cities would be "autonomous" (...), in effect prohibiting Greek cities from forming leagues, alliances or coalitions. Sparta was to be the guardian of the peace, with the power to enforce its clauses. The effects of the war, therefore, were to establish Persia's ability to interfere successfully in Greek politics, to atomize and isolate from one another Greek city states, and to affirm Sparta's hegemonic position in [Greece]." [Wikipedia]