ISTANBUL/BEIRUT (Reuters) - As Islamic State insurgents threaten the Turkish border from Syria, Turkey is struggling to staunch the flow of foreign jihadists to the militant group, having not so long ago allowed free access to those who would join its neighbour's civil war.
Thousands of foreign fighters from countries including Turkey, Britain, parts of Europe and the United States are believed to have joined the Islamist militants in their self-proclaimed caliphate, carved out of eastern Syria and western Iraq, according to diplomats and Turkish officials.