On Sunday morning, I was in Brussels at a conference organised by the German Marshall Fund. The city was tense, following the arrest a couple of days earlier of Salah Abdeslam, a leading suspect in the Paris bombings in November, although nobody could foresee that, two days later, Brussels itself would come under attack.
In retrospect, the Sunday morning session at the GMF conference was focused on issues that now seem even more urgent. One of the speakers was Yves Goldstein, who runs the office of the president of the Brussels regional government.
Mr Goldstein pointed out that the population of Brussels is 25 per cent Muslim. He insisted, with evident sincerity, that the mixed nature of the city, which has French, Flemish and EU quarters, was a source of cultural richness. But he also argued that Brussels faces its most serious security problem since the second world war since, as he explained, a substantial proportion of the young Muslim population of Brussels, regarded Isis terrorists as “heroes”.