The largest neighbor to the ISIS caliphate, Turkey has joined the US coalition against them, though they have so far declined to play any role in the war itself. Turkish citizens are joining in droves, however, on the side of ISIS.
The long-standing Turkish support for the Syrian rebellion in general has meant a lot of fighters flowing across the border, and at least 1,000 of ISIS’ current fighters are believed to have come from Turkey.
Turkey’s stance on ISIS is driven by the concern for 49 Turkish hostages held by ISIS since June. The Turkish government has banned media coverage of the hostage situation.
But it is more or less undeniable that Turkey’s refusal to let the US use their bases for the ISIS war is informed by the hostage crisis, and the fear of a backlash if the government gets the hostages killed by backing the US. Turkey has insisted their bases can only be used for humanitarian aid shipments.
The problem of ISIS recruiting exists across the West, but Turkey’s close proximity means that as the war escalates, it will continue to serve as one of the steadiest sources of new fighters for the movement.
So much for the notion of Turkey as a modern, secular, "western" nation ready to join the European Union.