Western fighters in Syria and Iraq have found some of their most willing recruits in tiny Belgium, a chilling trend highlighted by the killing of suspected terrorists by police on Thursday and which likely has its roots in the despair many feel at home.
Belgian police killed two men who opened fire on them during one of about a dozen raids against an Islamist group that federal prosecutors said was about to launch "terrorist attacks on a grand scale".
While the attack on satirical French newspaper Charlie Hebdo has focused the threat of radicalized Muslims in France returning from Syria, per capita Belgium is the European country providing the highest number of citizens to fight with Syrian rebels in recent years, data shows.
Even in absolute numbers, Belgium is third only to much larger France and Britain, with nearly 300 citizens travelling to fight between late 2011 and December 2013, according to the International Centre for the Study of Radicalisation.
The government estimates 170 Belgians are thought to be in Syria and another 40 are thought to have been killed, according to Belgian Foreign Minister Didier Reynders, who said returned fighters are subject to investigation and monitoring.
"We have seen Belgium at the centre of things for quite some time," said Matthew Levitt at the US-based Washington Institute and who regularly travels to Belgium to study the issue.
"You can see just walking around the capital," he said.
Brussels is best known as the headquarters of the European Union. But away from the glass and steel buildings of EU institutions, joblessness among 18-to-25 year olds runs as high as 50 percent in the commune of Molenbeek across the city's industrial-era canal.
While it is difficult to say exactly why so many young Belgian Muslims are heading to Syria, the seeds of anger and disenfranchisement are sown in the city's poorer quarters, according to former justice minister, Laurette Onkelinx.
"Despair is certainly one of the key explanations," she told public broadcaster RTBF. "When you are in despair, when you have no future, you are much easier prey to preachers of hatred."
Belgium has one of the highest percentages in the industrialised world of young people who are not in employment, education or training, according to the OECD.
Many children of immigrants from North Africa, who parents came to work in Belgium's steel plants in the 1960s, feel marginalized now that the car plants and factories where they would have found work two decades ago have closed.
Many also face discrimination for being Muslim, the largest minority religion in Roman Catholic Belgium and who make up about 6 percent of the population. Others were made to feel more ostracized by the extreme right Vlaams Belang party, which promoted intolerance of Muslims in the northern Flanders region.
Inspired by radical Islamic preachers in Britain, the group Sharia4Belgium emerged in 2010, encouraging Belgian Muslims to leave to fight in Syria, although its leader is in prison and the group has now disbanded.