So why is repetitive threat disorder so tenacious? Like blame al-Qaida syndrome, it is because it serves a variety of institutional interests.

Many have suggested that there is a deliberate conspiracy to maintain repressive legislation in place, scare citizens into acquiescence and maintain significant budgets for security establishments around the world. Indeed, some might draw parallels with the more grave condition outlined earlier, the blame al-Qaida syndrome. Certainly the two often go together.

However, there is little evidence of any kind of conscious, concerted effort. The conflicts of the last decade have created a huge counter-terrorist industry (of which specialist reporters and authors are necessarily a part). All wars end up generating new interest groups and beneficiaries. These are no different. For security services, threat is the guarantor of funding. For researchers, it means grants. For reporters, stories. There is a momentum here that is hard to stop.