How does a small city in a small country nestled between Germany, the Netherlands, France, and Luxembourg become the jihadist capital of Europe?

Belgium’s capital was once again thrust into the spotlight when two of the eight terrorists that struck Paris on Friday were identified as Brussels residents (paywall). Prosecutors have also revealed that two of the cars used by the Paris attackers were rental cars first hired in Brussels; one was found near the Bataclan concert hall, while the other was near a Paris cemetery. This is the fifth terrorist incident in the last in 18 months that has been linked with Belgium.

The country is Europe’s leading supplier of jihadists, as it has the highest number of foreign fighters per capita in Iraq and Syria in the EU:

Armed police raided the Brussels suburb of Molenbeek on Sunday and Monday, arresting seven people believed to be connected to the Paris attacks, and returning focus to this rundown, densely-populated area with a large Muslim population. When authorities investigated the assassination of anti-Taliban leader Ahmed Shah Massoud in 2001, the 2004 Madrid bombings, last year’s Jewish Museum shooting in Brussels, and the Amsterdam-to-Paris train attack in late August, their lines of enquiry led them to Molenbeek.

This has led some to describe the neighborhood as “Europe’s jihadi central.” “I notice that each time there is a link with Molenbeek,” Belgian prime minister Charles Michel said on Belgian television Sunday morning. “This is a gigantic problem.”

The mayor of Molenbeek (pop. 90,000) has called her district “a breeding ground for violence” and it’s easy to see why. Molenbeek’s unemployment rate is 30%, treble the national average, with youth unemployment thought to be around 40%. Some suggest the issues of poverty, overcrowding, as well as the government’s failure to integrate immigrants, has created a hotbed of jihadism.

In the last few years, the neighborhood has been at the heart of a thriving black market where a high-powered weapon can be bought in record time. “With €500-1,000 ($535-1,070) you can get a military weapon in half an hour,” Bilal Benyaich, a researcher into the spread of radical Islam in Belgium, told Reuters. Brussels’ struggle to deal with gun control has Benyaich comparing it to a major American city—surrounded by gun-free Europe.

While residents of Molenbeek say its reputation has been widely exaggerated, the true extent of radicalization in the neighborhood is hard to know due to Belgium’s fragmented politics. The country is split by French and Flemish speakers; in Brussels alone, there are six police departments and 19 mayors, which hampers attempts to have a united approach in preventing arms-smuggling and thwarting terrorist plots.