Refugees and migrants arrive on the Greek  island of Lesbos after crossing the Aegean Sea from Turkey on November 10, 2015. Lesbos and other Greek Aegean islands are at the forefront of the greatest migration challenge facing the European Union since World War II. Over 600,000 migrants and refugees, mostly from war-torn Syria, have landed in Greece this year, but nearly 500 have died in the Aegean. AFP PHOTO / ARIS MESSINIS        (Photo credit should read ARIS MESSINIS/AFP via Getty Images)