In a swiftly changing Europe, the decline of terrorism from its bloody peaks of more than a decade ago would seem inevitable. Extremist ideologies are fading, after all, so recruiting militants to fight for anachronistic or lost causes ought to be growing more and more difficult. Besides, notes Paul Wilkinson, director of the Research Institute for the Study of Conflict and Terrorism in London, "it is no longer fashionable for young people on the left to see terrorism as glamorous and romantic. It's regarded as a futile gesture." Yet the virus is proving surprisingly resistant.
In Britain last week the outlawed...