A multitude of factors makes isolating threats and controlling them incredibly difficult, however. Even when German intelligence and law enforcement identifies individuals with terrorist links and inclinations, a lack of corroborating evidence means the state often cannot act to prevent future incidents.

Law-enforcement officers are aware of the need to strike a balance between prudence in surveillance and overreach: “Because the objective justification for such decisions is often so difficult to identify, police officers and domestic intelligence agents are calling for clear guidelines on how classifications are to be made and what measures follow from those classifications. ‘We urgently need a nationwide approach,’ says a source at the Office for the Protection of the Constitution. ‘Otherwise nobody has a clue’” (“Targeting Terrorists: Germany’s Dilemma in Dealing with Islamist Threats,” Der Spiegel, March 23, 2017).

Germany’s experiences are not unique. The rest of the European Union, the United Kingdom and the United States all struggle with tracking, classifying and surveilling individuals suspected of extremist ties or behavior.

We may not see intricately planned, large-scale terror attacks like that of Sept. 11, 2001, but the newer brand of low-tech, impromptu attacks involving knives, vehicles and improvised weaponry in crowded urban spaces may prove to be even more effective at spreading fear and disrupting everyday life in the West.

“The potential threats of today, it seems, are not generally college-educated attackers like the 9/11 perpetrators in Mohammed Atta’s circle, who spent years planning the attacks on New York and Washington. For today’s IS- [or ISIS-] inspired attackers, a driver’s license, a knife or an ax are sufficient” (ibid.). As citizens demand protection, law-enforcement and intelligence agencies will need to adopt new methods to challenge the ever-changing face of terror. (Source: Der Spiegel.)