Spoiler: immigration
Via The Guardian:
Two days after the 9/11 attacks in 2001, a 31-year-old called Nizar Trabelsi was detained in Uccle , on the outskirts of Brussels. The former footballer of Tunisian origin was eventually sentenced to 10 years in prison for an intended attack on a Nato base.
In 2003, another militant of Tunisian origin detained in Belgium was sentenced to six years in prison for his role in a Brussels-based network which supplied fraudulent documents that had allowed the killers of an Afghan commander, Ahmed Shah Massoud , who fell victim to a suicide bomber two days before 9/11, to reach their target.