An image of a US P8 Poseidon plane can be seen on a monitor in the cockpit of a Royal New Zealand Air Force P3 Orion while flying to the search zone to help find missing Malaysia Airlines flight MH370, over the Indian Ocean on March 31, 2014. No time limit will be imposed on the search for MH370 because the world deserves to know what happened, Australian Prime MinisterTony Abbott said, as a ship equipped to locate the plane's "black box" prepared to set sail. AFP PHOTO / POOL / Rob GRIFFITH (Photo credit should read ROB GRIFFITH/AFP/Getty Images)
Refugees stand behind a fence at the Hungarian border with Serbia near the town of Horgos on September 16, 2015. Europe's 20-year passport-free Schengen zone appeared to be a risk of crumbling with Germany boosting border controls on parts of its frontier with France as migrants desperate to find a way around Hungary's border fence began crossing into Croatia. With a string of EU countries tightened frontier controls in the face of the unprecedented human influx, the cherished principle of free movement across borders -- a pillar of the European project -- seemed in grave jeopardy. / AFP / ARMEND NIMANI (Photo credit should read ARMEND NIMANI/AFP/Getty Images)