"Quickly" does not mean immediately. In 498 the Athenians sent twenty ships under Melanthius along with another five ships from the Eretrians to aid the Milesians. The Milesians and their allies marched to Sardis, burning the city. The Ionians were repelled from the city by the citadel's garrison, and when the Ionians were routed by the Persians pursuing them to Ephesus the Athenians and Eretrians ended their support for the Milesians and went home. Herodotus describes no particular order that went out to the Athenian expedition, although there must have been some resolution from the Assembly, and moreover the expedition had been grounded for some time already.

A few things must be said here. For one, when the Greeks speak of ships going here, there, or anywhere, they don't just mean ships hanging out and doing ship things. Ships were not simply sea vessels, they were a means of transport, carrying their own compliment of marines and whatever additional troops were carried on board for any given expedition. The dispatch of ships was not necessarily the dispatch of a naval force, but also of a land force operating overseas. Such expeditions were routinely, especially by the Athenians, spoken of in terms of numbers of ships rather than numbers of men involved, in no small part no doubt due to the standardized compliments of marines on board Athenian warships. Furthermore, ancient warships were not eighteenth century ships-of-the-line. They did not hang out in open ocean for months or even years at a time. The various galleys used in warfare, but especially triremes, were weapons first and ships second. The were decidedly unseaworthy. Topheavy with masts up, relatively flimsy, and, in the interests of speed, using as much space as possible they were not particularly great sailors, though they could move extraordinarily fast under good conditions. Triremes lacked any space for their rowers and crew to sleep, and did not have the necessary space to store water and provisions. This, along with the difficulties involved in nighttime sailing, meant that warships were usually beached at night to allow the crew to sleep, and usually again at midday to allow the crew to forage or buy food at market. They stayed close to shore, where they were more seaworthy, hopping from island to island across the Aegean and avoiding large stretches of open water that might keep them from sight of land for more than a day or so. Like this they could move with remarkable speed--a normal journey from Athens to Ephesus took around three days--but with these limitations. Finding and relaying a message to a ship whose route was known was not much of a problem, provided you were fast--the Athenians did it 427 when they dispatched a double-crewed ship to catch the one they had already dispatched to Mitylene with orders to overturn the previous order to slaughter the citizens. An entire fleet, which would have to move much more slowly, would have been little trouble at all, even if the expedition had not been ultimately a landed one