CBSN's panel of global experts on radical Islam discuss why Brussels has become a recruiting hotbed for ISIS. The panel included; CEP Executive Director David Ibsen; Erin Saltman, a senior researcher at the United Kingdom's Institute for Strategic Dialogue; New York Times reporter Rukmini Callimachi, who focuses on ISIS and the Middle East; Richard Barrett, a former British intelligence officer and senior vice President of the Soufan Group; and Farah Pandith of the Council on Foreign Relations.