“That’s a smuggler,” the captain of the coast guard’s lifeboat says, swinging the vessel around and opening up the throttle, the boat cutting through the water on a frigid January night. [...] the lifeboat, designed for search-and-rescue operations rather than high-speed chases, is no match for the smuggler’s speedboat. The smuggler ignores the searchlight, the shouts and the warning shots fired by the Greek coast guard, deftly navigating his small vessel onto a tiny patch of beach. Hour after hour, by night and by day, Greek coast guard patrols and lifeboats, reinforced by vessels from the European Union’s border agency Frontex, ply the waters of the eastern Aegean Sea along the frontier with Turkey. Hours spent on patrol shows the near-impossibility of sealing Europe’s sea borders as some have demanded of Greece, whose islands so near to Turkey are the most popular gateway into Europe. [...] unless a Turkish patrol stops a migrant boat and returns it to Turkey, there is little Greek or Frontex patrols can do once it has entered Greek territorial waters but arrest the smugglers and pick up the passengers or escort the vessel safely to land.