Even before the war in Gaza, authorities have been warning of rise in Islamist terrorism on the continent

For months now, authorities charged with keeping Europe safe from Islamist extremist violence have been sounding the alarm. In May, Dutch security services warned that the terrorist threat from Islamic State to Europe had increased. The same month, the French interior minister said the risk of Islamist terrorism was rising again and that his own country was being targeted, as well as its neighbours.

In recent days, these pessimistic forecasts appear to have been vindicated. France is deploying 7,000 extra troops on to its streets after a teacher was fatally stabbed on Friday in an attack that Emmanuel Macron condemned as “barbaric Islamic terrorism”. The suspected attacker swore an oath of allegiance to IS in an audio recording on his phone shortly before the killing, prosecutors have said.