Europe must brace for new, varied IS attacks

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Gilles de Kerchove, the European Union's Counter-Terrorism Coordinator, said it was impossible to know for sure how many militants were already in Europe plotting. A report on Friday by the EU's Europol policy agency referred to dozens.

European Union's Counter-Terrorism Coordinator Gilles de Kerchove is seen during an interview with Reuters in his office in Brussels, Belgium December 2, 2016. REUTERS/Alastair Macdonald

Some 2,500 Europeans may still be fighting in the Middle East, de Kerchove estimated in an interview with Reuters. But as they face setbacks in Mosul, Aleppo and elsewhere, Europe must track them if it is to contain a diaspora of trained militants like that which followed the 1989 Soviet withdrawal from Afghanistan.

"We have to be prepared because some of them will come to Europe," said de Kerchove, a veteran EU official whose Brussels office is packed with books and souvenirs from nine years of intensive travel and talking with Europe's troubled neighbors.

"They may try to come back home and we don't want to repeat the mistake we made in the late 80s when the Russians left Afghanistan and we left these mujahideen ... in the wild."

Many of those fought in Algeria's bloody 1990s and went on to operate in conflicts from Chechnya and Kosovo to Yemen.

Some Europeans, among them also wives and children of fighters, may choose to stay in the Middle East even if IS loses its territorial grip. Others may go further afield, with lawless Libya already looking like a new base for European militants and the movement likely to go on recruiting over the Internet.

"The physical caliphate ... is collapsing but we still have the virtual caliphate and this allows the organization to direct attacks," de Kerchove said.

In his post since 2007, the Belgian lawyer said the past two years have seen an "impressive" leap forward in intelligence cooperation among EU states and a tightening of law and practice on Europe's borders in response to the variety of IS attacks that have included mass killings in Paris, Brussels and Nice.

"We have nearly fixed most of the loopholes," he said of what Europe could do internally to combat the Islamist militants who pose by far the bulk of violent threats.