In 2015, Turkey became a kind of human superhighway for refugees fleeing to Europe from Syria and elsewhere, a migration of at least 1.3 million people that had a seismic impact on the politics of the European Union. Many of the bloc’s leaders now fear a repeat, yet it is far more difficult for desperate Afghans to reach Europe than six years ago.

New concrete, metal and razor wire walls, together with drone surveillance, beefed up border patrols and catch-and-return policies have made the route to Europe more difficult, dangerous and costly.