The Islamic State's attack in Barcelona, Spain, which killed at least 14 and wounded approximately 100 others, was the first time the group attacked the country, but it should come as no surprise.
There are several reasons behind why the group would target Spain. First, because it had the means to do so. ISIS may be losing massive amounts of territory in its so-called land caliphate in Syria and Iraq, but that hasn't stopped the group from continuing attacks abroad. Spanish authorities believe the perpetrators of the Barcelona attack belonged to a cell, which ISIS has used to engage in attacks abroad before. In some cases, members of these cells are trained, experienced fighters.
"There have been cells, sometimes those cells have at least one person, sometimes several, who have had some kind of exposure to ISIS, sometimes the exposure has been to different kinds of trainings," Anthony Cordesman, the Arleigh Burke Chair of Strategy at the Center for Strategic and International Studies, told Circa in an interview.
ISIS's most infamous cell was responsible for the 2015 attacks in Paris. Authorities believe some of them may have trained in Syria prior to the attacks. Some were later seen in ISIS propaganda videos. There have also been attacks that were simply inspired, with no direct involvement from the group's leadership. ISIS propaganda often specifies potential targets and even gives step by step guides on how to conduct a successful attack.
Cordesman also noted that Muslim migrants from North and sub-Saharan Africa often have a difficult time integrating into the Spanish culture, which limits career, educational and housing opportunities. Barcelona, and the surrounding region of Catalonia, is home to more than half a million Muslims. The region is also home to several Salafist mosques. Salafism is the hardline sect of Islam from which many jihadist groups draw their ideology.
Strategy also plays a key role. ISIS has long encouraged its followers to engage in attacks against the U.S. and its coalition fighting the group in Iraq and Syria, known officially as Combined Joint Task Force Operation Inherent Resolve. Spain's role has largely focused on training, and it does not engage in air combat operations, but that apparently makes no different to the extremist group.
History also has a part to play. ISIS ideologues often fantasize about the ancient Islamic empires, one of which actually controlled Barcelona in the 8th century. It is not uncommon to see Islamists post pictures of Spain's mosques on the internet, pining for the days when the country was part of the old caliphates. ISIS Telegram channels almost immediately praised the attack after it occurred, reposting threats to "reconquer al-Andalus," as Barcelona was known while under Muslim control.