Business Insider reports: At least 30 people were reported killed and dozens more wounded after explosions ripped through Zaventem Airport and a metro station in Brussels on Tuesday morning.

The attacks came days after Saleh Abdeslam, a suspect in last year’s Paris attacks, was arrested in the Belgian capital, which is also the de facto capital of the European Union.

Clint Watts, a senior fellow at the George Washington University Center for Cyber and Homeland Security, said on Tuesday that the Brussels attacks were in line with an “iceberg” theory of terrorist plots.

That theory purports that, just as for every iceberg seen above water, the underlying mass of a terror network and its plots are not immediately visible — or, “for every attacker, there are usually three to four additional people who helped facilitate the plot.”

“That the eight attackers in Paris used more explosive belts than ever before seen in the West suggests a sizeable European terrorist facilitation network,” Watts wrote for War on the Rocks in November.

He added: “The iceberg theory of terrorist plots suggests we should look for two, three, or possibly four dozen extremist facilitators and supporters between Syria and France. This same network is likely already supporting other attacks in the planning phase.” [Continue reading…]