Summary: How serious a threat to western security is the extremist group that calls itself Islamic State? According to those governments now backing military action against the jihadis the danger is very real - not least from foreign fighters, battle hardened in Syria and Iraq, who return to homes in the west. HARDtalk speaks to the EU counter-terror coordinator, Gilles de Kerchove - does the EU have a coherent response to the Islamic State challenge?
