'Lone wolf' attackers are elusive but can be traced on the internet
Recent high-profile terror attacks pose a new challenge for police and intelligence services. All seem to be the work of 'lone wolf' actors. Yet police and intelligence services, by the nature of their work, target groups. It's possible to adjust that focus, but that would require Western societies to make an important trade-off.
On Monday, a 17-year-old Afghan asylum seeker gravely wounded four fellow passengers with an axe and a knife on a regional train near Wuerzburg in Germany before police shot him to death.
The attack continues a series of terrorist acts by loners: the shooting in Orlando in June; the truck rampage in Nice last week; the police shootings in Dallas and Baton Rouge. Islamic State claimed responsibility for Orlando, Nice and Wuerzburg, but that's merely in keeping with its status as the umbrella brand for Islamist terror. The killers weren't members of any terror group, and they weren't acting on anyone's orders.