GREECE’S migrant crisis is getting worse. Macedonia has closed its border to all but a trickle of migrants, following the example of Austria and other countries along the so-called West Balkans route to Germany. Yet desperate Syrians and Iraqis continue to arrive at the Idomeni crossing point. On February 29th Macedonian police used tear gas against scores of migrants trying to break down the border fence. As _The Economist_ went to press, more than 12,000 people were crammed into a tent camp with facilities for only 1,500. Food is in short supply. “It’s a tense situation,” says Panagiota Siafaka, a social worker with the UN High Commission for Refugees. So long as the border remained open, Greece could manage the flow of arrivals from Turkey. Now almost 30,000 migrants are bottled up in Greece. Nikos Kotzias, the foreign minister, expects the number to reach 150,000; local aid agencies worry that 200,000 people may arrive in March alone. Reception centres around Athens for migrants are hopelessly overcrowded. Half a dozen new ones, mostly refurbished former military camps, are quickly filling up. Local and international...