Brussels was the scene of multiple explosions on March 22, highlighting the persistent vulnerability of soft targets to simple, effective attacks — as well as the willingness and capability of militants in Western Europe to undertake those attacks.
Belgian authorities have confirmed that at least 13 people were killed and more than 35 others were injured in twin blasts at Brussels' Zaventem airport. An initial explosion took place near the American Airlines check-in counter. A second device then reportedly detonated near the Brussels Airlines ticket counter. Shortly thereafter, another explosion was reported at the Maelbeek metro station, close to the heart of Brussels and EU institutions. As a precaution, all metro and rail services in Brussels have been suspended, according to AFP, and flights have been diverted away from the city. The Belgian government has raised its official alert level to 4, the highest level.
The Brussels blasts are a striking reminder of the difficulty of preventing attacks against soft targets. Unlike hard targets, which tend to require attackers to use large teams of operatives with elaborate attack plans or large explosive devices to breach defenses, soft targets offer militant planners an advantage in that they can frequently be attacked by a single operative or small team using a simple attack plan. In addition, attacks against transportation-related targets such as metro stations and airports allow attackers to kill large groups of people and attract significant media attention.
Militants have long targeted the soft area outside airports' security sectors. For example, a Palestinian militant group known as the Abu Nidal Organization attacked ticket desks in Rome and Vienna in December 1985, and a ticket desk at Los Angeles International Airport was attacked by a gunman in July 2002. In 2011, a bomb attack at Moscow's Domodedovo International Airport killed 35 people and injured more than 160. The departure and arrival areas outside of airport security usually provide a sizable pool of potential victims who can be attacked without having to sneak weapons past security. This is why travelers should minimize the time they spend on the "soft" side of the airport.
The Brussels attacks come in the wake of the March 18 arrest of Salah Abdeslam, a surviving member of the cell that conducted the Nov. 13 Paris attacks, in the city's Molenbeek neighborhood. There have been media reports that Abdeslam was planning additional attacks in Europe, and Belgian officials were seeking two of his associates. It is unknown if those associates were involved in the Brussels attacks or if the attacks were conducted by other operatives. Brussels has been a hotbed of jihadist activity, and there are many Belgian citizens fighting with the Islamic State, Jabhat al-Nusra and other jihadist groups in Syria and other theaters of jihad. In June 2014, a gunman associated with the Islamic State attacked the Jewish Museum in Belgium. Most notable, much of the planning for the November attacks in Paris was also conducted in Belgium, and Belgian officials have braced for additional attacks inside the country.
The March 22 attacks were simple but effective, in part because they were directed at people concentrated in restricted spaces — an optimal place to create a high body count with a small suicide device. Targeting the American Airlines ticket counter is quite symbolic, indicating that it was likely an attempt to kill U.S. citizens.