Spain has had a long history with terrorism, but much of the violence was carried out by ETA, the Basque separatist group, which declared a truce in 2011. Catalonia, where Barcelona is located, is home to a powerful separatist sentiment, but that secessionist movement has not been violent. The most high-profile recent attack, however, was attributed to al-Qaeda in 2004 when near-simultaneous attacks on Madrid’s commuter train system killed 192 people and injured more than 2,000. Those attacks, which came three days before the country was set to vote in general elections, was the worst in Spanish history.
The Spanish government maintains a national terrorism alert level in response to terrorist attacks in Europe and elsewhere, as well as information held by its security agencies. Since 2015 the Spanish authorities have assessed the threat level as “high”, the second highest level (Level 4 out of 5). The current alert level is available on the Spanish Interior Ministry's website (in Spanish).Although not a target of the scale of attack seen in 2004, Spain maintains its alert level at 4, the second-highest level. It has been at that level since 2015. Enhanced security measures were directed at crowded spaces, prominent buildings, and mosques, according to Euronews.
“The armed forces are not directly involved in the current state of alert, as it is the case of France, for instance, but they remain under alert,” the Interior Ministry told Euronews. “That means they could be called to support security forces in meeting objectives if it is truly needed and that they may have to act imminently.”
El Pais, in a news report in June, noted “a silent ‘army’ of more than 3,000 officers from the security forces, spies, prosecutors, judges and analysts are working in the shadows in order to avoid another attack.” Here’s more:
Currently, more than a thousand people are on the radar of the Spanish police, while 259 people are being investigated by the courts and 500 telephones are being tapped as part of dozens of investigations. That’s according to confidential information to which EL PAÍS has had access. The mission is so complicated that in their reports to the government the anti-terrorist services all arrive to the same, worrying conclusion: a new attack is inevitable.
The El Pais report noted that since 2005 Spain has arrested more than 700 people in connection with terrorism convicted dozens, and imprisoned 120 people. It has also, the newspaper reported, foiled several attacks during the planning stage. But the manner of Thursday’s attack shows that despite the best preparations it’s difficult to stop a man in a truck from causing harm.
The attack at Las Ramblas matches several recent high-profile terrorist attacks across Europe, including in Nice, France, and London. What’s different about such attacks is the number of casualties vary widely. A recent car and knife attack at Ohio State in 2016 injured a few people; one woman was killed in last weekend’s attack in Charlottesville, Virginia; six people were killed in the Westminster Bridge attack in London; and more than 80 people were killed in Nice. But as my colleague Uri Friedman wrote in April after a truck was used to strike pedestrians in Stockholm: “But the nasty truth about violence so basic—requiring no training, weapons, or collaboration with a terrorist group, nothing more than access to a vehicle and the ability to drive it—is that it is extremely difficult to prevent. The less complex the terrorist plot, the harder it is to thwart.”