I don't know. There's enough exaggeration in this essay that I am not sure he really knows what he is talking about. For instance, the National Front... I remember doing some research on them for a French class and they didn't sound much worse than Archie Bunker on a cranky day. From what I remember. Of course, that was 12 years ago, but...
I was living in Europe during the hey-day of soccer hooliganism. It still lurks under the surface in the UK, France and Italy. All they need to go berserk is an acceptable target. At which point gangs of skin-heads will descend on the muslim quarters with knives, baseball bats and an attitude...