Violent conflict, not traditionally a feature of life in Britain, arrived with brutal force this weekend. Angry mobs targeted mosques and attacked hotels housing migrants, setting at least one on fire. Businesses were looted, and groups of men have been seen gathering in force, holding weapons and attacking others. Although more than 400 arrests have been made so far, and no doubt more will follow, the police have often appeared outnumbered and unable to deploy sufficient force to quell the riots.