According to the United Nations, 83 percent of September arrivals came from Syria, Iraq and Afghanistan, where most of those who could and wanted to flee are already gone. Things could get ugly fast if a new war breaks out in the Middle East. Lebanon, already overpopulated with Syrian refugees, is one of the more distinct possibilities as the rivalry between Saudi Arabia and Iran heats up. A new refugee stampede could easily overwhelm the feeble barriers Europe has managed to construct. Neither Turkey, whose relationship with Europe is undergoing a cold phase, nor Libya would be able to staunch another flood.

Europe is not ready. The refugee relocation scheme it hastily concocted in 2015 is barely working: In more than two years, only 32,000 people have been moved from Greece and Italy. On the Greek island of Lesbos, more than 5,000 people are living in a facility meant for 1,400. In the Italian town of Ventimiglia, on the French border, 600 extremely miserable migrants and asylum seekers created enough tension for the mayor to appeal to the EU for help. But other European nations are unwilling to take the immigrants; three of the four countries of the so-called Visegrad group — Poland, the Czech Republic and Hungary — are especially adamant, creating perhaps the most important split in the EU today. All attempts to shame them into taking in more people have failed, and the European Commission is now suing the three countries to force them to accept mandatory resettlement.