The arrests on Thursday of additional suspects in the Brussels terror attacks supports our assessment that this operation involved a much larger cell than the attack teams who targeted the airport and metro station. In sharp contrast to the attack in San Bernardino, where Syed Rizwan Farook targeted a location requiring little pre-attack preparation (his work place), the Brussels attacks continue to show a high degree of operational planning. The decision to attack multiple locations, using different teams, appears to indicate this operation adhered closely to our Terrorist Attack Cycle, and likely involved several different teams of operatives covering Surveillance, Logistics and Attack.
The location of the airport attack in particular appears to have taken a page from the al-Qa’ida playbook. By detonating the IEDs close to US and British airline counters, as well as a major US business (Starbucks), the attackers may have chosen this location to kill US and British nationals as well as for symbolic purposes. It is possible that a careful review of archived CCTV footage of the attack site will show previous visits to the location by the attackers or, more likely, the surveillance team(s). Based on video footage captured ahead of other terror attacks, this archived video will likely show team members photographing and possibly pacing off distances in the terminal in an attempt to determine bomb placement for maximum impact.
We continue to believe the gloves worn by the attack team may have been used as a signaling device to an advance team already at the airport terminal. Based on our experience and understanding of the terrorist MO, the attackers wore one glove because they wanted to be noticed. Not by law enforcement officers or other passengers, but by someone inside the terminal who would have been prompted to look for this visual bonda fides signal. Based on the Terrorist Attack Cycle, the advance team would have pre-positioned themselves in order to give a go/no go signal to the attackers. Although we have seen conflicting reports describing weapons found at the airport, if true, this could indicate the advance team was also prepared to provide security if anyone attempted to interfere or stop the attack.
While law enforcement and intelligence agencies will continue to uncover new clues in the coming weeks, it is clear this operation was well-planned and involved a considerable number of people. It is also highly likely these cells simultaneously surveilled other targets (as evidenced by the video footage captured of the Belgian nuclear official) and that other operations were in the planning stages.