Some Belgians say the terrorist attacks have brought the country together, and that's what the country needs. Others says the bombings show the country needs to split, with one part made of French-speaking Walloons, the other Dutch-speaking Flemish.
"We want to get rid of Belgium," says Sam van Rooy, a spokesman for the Vlaams Belang Party, or Flemish Interest Party, on Belgium's far right.
"It's actually a non-state. It has two different peoples, two different cultures, and we see it doesn't work. And it's one of the causes that we had these terror attacks now," he adds.
Asked if he considers himself more Flemish than Belgian, he responds, "Yes, of course, no question. I only feel Flemish."
Vlaams Belang represents a view heard throughout Europe: that immigration has spelled disaster.
When van Rooy looks at Brussels' diverse population, he doesn't like what he sees.
"I see actually a city that is more and more looking like an Arab country, or an Islamic country," he says. "I think it's really bad for freedom, for our democracy, for our identity. I call it Belgistan."
And his prescription?
"I call for these Muslims to see the truth about Islam and to either leave Islam or reform it fundamentally," he adds. "The migrants who are here either adapt to our way of living, to our culture, to our values, and if they don't, they should leave. It's very simple."
The Flemish Interest Party wants Belgium to close its borders to immigrants, especially those from Muslim countries.
And van Rooy blames the European Union, which is headquartered in Brussels, for what he says is a dangerous "open borders" policy.
"I think if your house has no door that is locked and can be opened when you decide to open it, well then, you don't have a house," he says. "We should go back to Europe like it was."
Just a few steps down the street from the Flemish Parliament is the Federal Parliament of Belgium, of which Dirk van der Maelen has been a member for 26 years.
Van der Maelen is a Social Democrat, which means in the elegant chamber of Parliament, he sits way to the left in the semicircle of members' chairs.
As we talk, we look up at a plaque bearing the Belgian national motto, in Dutch and French, which translates as "unity makes strength."
It refers to Belgium's 19th century united front against its former ruler, the Netherlands. For van der Maelen, that slogan is just as appropriate now.
"I am always in favor of staying one country," he says. "I think that in times of globalization, in times that we try to construct Europe, it looks to me that it is very stupid to split up."
He knows last week's terrorist attacks will only make these Belgian tensions worse.
"There are parties who are for the moment exploiting fear and the anger, which is in the society, so I am worried about the future," he says.
For van der Maelen, the far-right, close-the-borders parties have a simplistic view.
"I don't think that any country — except maybe North Korea, where nobody wants to go — but I don't see one normal country in the world who succeeds in closing itself from the rest of the world," he adds.
Where van Rooy sees the European Union as a grave threat, van der Maelen sees it as a key to Belgium's security.
"I think it's the only opportunity we have to have any influence on the way things are changing in the world," he says. "Belgium is too, too, way, way, way, too small," he argues.
The country needs both more European unity, van der Maelen says, and more Belgian unity.