Getting to Syria has generally been easy (...) All a fighter needs is a one-way ticket to Istanbul. From there, most take domestic flights to one of the border towns along Turkey’s frontier with Syria that runs for 822km (511 miles): locals dub these internal flights the “jihadi express”. Newcomers stay in safe houses before being smuggled across or passing through Turkish passport control using fake Syrian ID cards.
The Soufan Group, a New York-based intelligence outfit, reckons that by the end of May as many as 12,000 fighters from 81 nations had joined the fray, among them some 3,000 from the West (see chart). The number today is likely to be a lot higher. Since IS declared a caliphate on June 29th, recruitment has surged. Syria has drawn in fighters faster than in any past conflict, including the Afghan war in the 1980s or Iraq after the Americans invaded in 2003.
While the overwhelming majority of foreign fighters in Syria are Arabs, Britons make up one of the biggest groups of Western fighters. But Belgians, Danes and others have a higher rate per person (see left-hand chart above). France, which has tighter laws against extremism, has also seen more of its citizens go off to wage jihad.