And after the carnage, the inevitable finger-pointing: fragmented law enforcement in this divided nation, as well as a lack of coordination between the 28 European Union members in fighting terrorism. And the breakdown runs deeper here -- Belgium has long struggled to govern itself.
That breakdown is blamed in part for how long it took to catch serial child murderer Marc Dutroux in the 1990s. Reforms since then have sought to improve that communication, but language differences remain an issue.
Belgium has struggled at times even to form a government, as long as two years most recently -- longer than Iraq took -- while some leaders in the Flemish north threaten to break away and form their own country.
The more affluent north, comprising about 60% of the population, became more powerful after the post-industrial decline of the coal and steel-producing Walloon south. The Flemish complain about supporting the less-affluent south.
One could liken the division to the drive by Quebec, where French-speaking separatists have so far failed to win votes there to break away from Canada. Some here suggest there should be a referendum.
Difficult to govern
Belgium is a relatively young country, younger than the United States, formed in 1830 after ending Dutch rule. Wedged between France, Holland, Germany and Luxembourg, Belgium has remained difficult to govern, with layers of administration and parallel structures serving the three official language groups -- Dutch, French and German.
One stark example of Belgian parochialism: it wasn't until 1998 that Belgium centralized its passport production, until then the responsibility of more than 500 town halls. That had made it easier to forge passports by stealing blank ones from local government buildings.
Brussels International Airport is an ongoing example of the clash between the north and south. Located just inside Flanders, its planes take off and often land over Francophone areas of Brussels and Wallonia, sparking bitter protests by the residents and leaders there.
Politics itself can complicate concerted action. Interior minister Jan Jambon has said he wants to clean up Molenbeek, the Brussels district where terror suspect Salam Abdelsalam was captured. But cooperation from the Brussels region and its French-speaking community is difficult, as Jambon is a member of the Flemish nationalist party N-VA.
Belgium 'more stable'
Whether Belgium can act in a more united fashion to tackle the terror threat remains to be seen.
Also before the Parliament is a European Commission proposal for a common border police and coast guard, not only to tackle the migrant crisis but also to counter terrorist activity. That is to be voted on by June.
In the meantime, Belgium is Europe's latest anti-terror battlefield, and ill-equipped to fight on its own.
Formerly with CNN, Chris Burns is a Franco-American journalist and media consultant with 25 years' reporting experience in Europe, the U.S., Africa, Central Asia and the Middle East. The opinions expressed here are solely those of the writer.