Nightmare: Lone terrorists

DW: Mr. Tophoven, what role do militants acting alone play in the current fight against terrorism?

Rolf Tophoven: If you mean individuals with a Salafist-jihadist background, then we're talking about someone who is a classic "lone wolf." Because he's not closely connected with a group; there are no warnings ahead of a sudden attack. Security officials have long feared that single actors pose a large threat, alongside organized terror cells. A man who's not on the radar with the police or with intelligence officers is like a "ticking time bomb." Self-radicalization can occur any time without anyone knowing about it, and the acts that follow are very difficult, if not impossible, to prevent.

So what can the authorities even do to identify such individuals?

They're monitoring many different Islamic centers in Germany, especially in large cities. The cells are largely known, but the authorities also watch people who are on the fringes of extremist activity. But you can only recognize a single actor in this environment if this person has drawn attention to themselves by making extremist statements or engaging in extremist activity. Otherwise, such a person flies under the radar.

Have there already been attacks by individual terrorists in Germany?

A person who becomes radicalized and plans an attack in isolation is a security official's worst nightmare. There was such a case in 2011. Nobody could have predicted that 21-year-old Arid Uka (pictured above), an unpresuming man from Kosovo, would shoot and kill two US soldiers and injure two others at Frankfurt airport. It was the first Islamist attack that German officials failed to prevent.

What do we know about such lone wolves motivated by Islamic extremism?

They're extremely frustrated. They don't see themselves as having much of a career; some find it difficult to integrate into society. They act out of a sense of desperation. That's what makes them so susceptible to the messages from Islamist terror organizations.

To what extent do such people look for information from terrorist groups online that could perhaps provide clues to their identity or potential targets?

Islamist leaders are always issuing calls to followers. They'll say things like, take what you can find - a knife or a car, and drive into a crowd of people, kill people however you can. The trend is towards small cells and simple methods that have maximum effect. That's why all the places where large crowds of people gather are especially at risk.

Are there any estimates on whether we can expect an increase in attacks being carried out by single actors and how many such people there might be in Germany?

You can't really give a credible answer to that question. There's no way of knowing whether attacks by single actors will increase. The number that you hear from the Federal Criminal Police (BKA) is that there are around 400 people considered to be a threat. The President of the Federal Office for the Protection of the Constitution, Hans-Georg Maaßen, once told me that every such person who is not on the radar presents a threat every single day. People who've returned from territory held by the so-called "Islamic State" are a threat when they create a network here. So the threat lies in networks forming among individuals who are prepared to commit terrorist acts.

Do you think that we need more monitoring of communication and more extensive data retention?

I've always advocated for this. The BKA has always requested this. But it's doubtful whether these would be successful methods of discovering previously unknown individual extremists. The laws governing such activities are tight. And the exchange of sensitive data between different EU security officials is severely lacking.

Rolf Tophoven is the director of the Institute for Crisis Prevention (IFUS) in Essen. He has decades of experience in researching terrorism.

This interview was conducted by Wolfgang Dick.