The arrest on Wednesday of nine Birmingham Muslims accused of plotting to kidnap a soldier has something familiar about it and also something eerie. The alleged abductors reportedly drew up a list of two dozen Muslims in the armed forces. They allegedly planned to seize and torture a 20-year-old who had served in Afghanistan, before beheading him on video, which they would disseminate over the internet. It would bring to British soil the atrocities inflicted on the reporter Daniel Pearl in Pakistan and on Nicholas Berg and Kenneth Bigley in Iraq.

To the cynical terrorist, such an operation serves two goals. The first is the familiar practical one. It separates populations, "heightens the contradictions". (By killing Catholic soldiers in Northern Ireland, the IRA sought to create a one-to-one identification between repression and Protestantism.) The second goal is the eerie, demonic one. Broadcasting atrocities aims to break a deep taboo and release the perpetrators' sympathisers from their inhibitions about shedding blood. It is likely that any such operation in Birmingham was more about bloodlust than separatism.