Tuesday’s devastating attacks in Brussels, in which more than 30 people died and scores were injured, are the latest phase of the war on Europe declared by the so-called Islamic State.
The attacks cast a dark shadow over last week’s triumph, the arrest of Salah Abdeslam.
The hope will be that Abdeslam, one of the leading members of the cell behind the Paris attacks, will provide crucial intelligence on the current state of IS’s network and its future plans.
Getting captured IS fighters to talk is one of the crucial ways in which Western intelligence services have built up the picture of its European network and in particular the role of its former commander, Abdelhamid Abaaoud.
The BBC’s Panorama programme has seen the transcripts of some important interrogations carried out by France’s equivalent of MI5, the DGSI. They reveal valuable details about the tactics used by Abaaoud to train and equip IS fighters in Europe.
Nicolas Moreau was one them. He was arrested in 2015 having left Nantes to fight jihad in Syria in 2014.
He, like many IS recruits, was a former petty criminal who had converted to Islam in prison and become disillusioned with life in France.
He told his interrogators he couldn’t stand the “injustice” and “couldn’t see any future in this country”.
He went on to provide valuable information about IS’s external operations department known as Amni, meaning “security”, that sends hand-picked trained fighters back to Europe to inflict death and destruction on their homelands.
“Each gets 50,000 euros (£40,000) to mount an attack,” Moreau said.