The mobilisation of jihadist foreign fighters that has taken place as a result of the conflict in Syria and Iraq has been unprecedented. According to the United Nations, up to 40,000 foreigners from nearly 100 countries have participated in the war. Not all of them will remain part of the movement. Many, have already become disillusioned, turned against their comrades, and “retired“ from fighting. Others, however, will turn up in other conflicts, become involved in terrorist networks, or use their credibility as “veterans“ to recruit new followers. There can be no doubt that the consequences of this mobilisation will be profound and long-lasting. In one of my recent books, I predicted that it will result in a “fifth wave“ of terrorism.

Much of the public interest in the foreign fighter phenomenon has focused on Western Europe and the Middle East. The situation in the Balkans, by contrast, has received comparatively little attention. This book is the first comprehensive account of who the foreign fighters from the Balkans are, where they come from, and how they have been radicalised. All the chapters are based on in-depth research and written by leading experts from the region. Their analysis and conclusions are based on empirical facts and a profound understanding of the social and political dynamics in their respective countries. It is this depth of local knowledge that makes the various chapters so interesting and informative.

Based on the conclusions, I am deeply convinced that tackling the threat of foreign fighters in the Balkans is vitally important for the Balkans and Europe more generally. Many of the countries in the region are young and have brittle institutions. The fault lines that have emerged from the wars of the 1990s are still present, and can easily be activated. Given how deeply shaken an old and seemingly strong country like France has been by recent attacks, one can only imagine the kind of impact that large-scale jihadist attacks would have in many of the countries in the Balkans.