Leela Jacinto writes: In the weeks since terrorists struck the Belgian capital, authorities and journalists have wasted no time mapping out the links between the Brussels and Paris attacks. Lost in all these lines connecting Europe’s gray urban landscapes are the sun-drenched hills, valleys, and towns of northern Morocco. And it is to Morocco that we must go to fully understand what has spurred young men to wreak havoc in Western European capitals.

At the heart of terrorist strikes across the world over the past 15 years lies the Rif. A mountainous region in northern Morocco, stretching from the teeming cities of Tangier and Tetouan in the west to the Algerian border in the east, the Rif is an impoverished area rich in marijuana plants, hashish peddlers, smugglers, touts, and resistance heroes that has rebelled against colonial administrators, postcolonial kings, and any authority imposed from above. For the children of the Rif who have been transplanted to Europe, this background can combine with marginalization, access to criminal networks, and radicalization to make the vulnerable ones uniquely drawn to acts of terrorism.

Nearly a decade later, the same jihadi tourism trail has led to the Paris and Brussels attacks. One of the latest Riffians to gain international notoriety has been Najim Laachraoui, the Islamic State bomb-maker who traveled to Syria in 2013, where he perfected his explosives expertise.  He’s one of the three men pushing trolleys in Brussels Airport on the morning of March 22. Laachraoui was one of two suicide bombers who blew themselves up at the airport.

Laachraoui was Riffian: a Belgian national predominantly raised in the Schaerbeek neighborhood of Brussels but born in Ajdir, a small Moroccan town with a proud Rif history.

The region’s baggage goes back a long way. The history of the Rif is choked with battles between Berber kingdoms in the precolonial era, which gave way to major wars and rebellions against the Spanish and French.

King Hassan II famously never visited his palaces in Tangier and Tetouan. Government services in the region were negligible, Islamists filled the void, and Wahhabi teachings spread like wild fire in the slums and shanties of cities like Tetouan. Today, the region has the highest rates of poverty, maternal death, and female illiteracy in the country, coupled with Morocco’s lowest growth indices. So, though the current King Mohammed VI has invested in the region and makes it a point to vacation in the Rif, the largesse has not trickled down to ordinary Riffians.

While Europe offered the sorts of economic opportunities for which the first generation of migrants was grateful, the next generation has struggled. The economic downturn since the late 1970s has not helped. The Belgian heavy industries and coal mines that once drew Moroccans from their villages have now shut down, leaving behind areas of urban blight.

But, lurking in the background of all this, there is still the Rif — a radicalizing factor all its own.

The baggage of neglect has affected even the relatively lucky Riffians who escaped poverty back home for Europe. The older generation arrived in then-French-controlled Algeria, Belgium, or mainland France only to find that, as residents of a former Spanish enclave, their French was not up to snuff. Neither, as Berbers speaking Amazigh languages and dialects, was their Arabic.

Under these circumstances, the old Riffian ways and mores of traditional codes of conduct, honor, justice, and suspicion of authorities were transplanted to Brussels neighborhoods and allowed to bloom and grow. Fairly or not, Belgian authorities describe the country’s Rif community as marked by lawlessness and a “tribal, more aggressive culture” that sets it apart from other immigrant communities.

These are the sorts of networks that the predominantly white Belgian and French security services now must crack and infiltrate.

This battle must be won on the streets, from Molenbeek to Tetouan.