This might be a daft question but why is the security threat of a terrorist attack on the UK currently set at ‘critical’? According to the MI5 website, ‘critical’ signifies that an attack is expected imminently.

A few days ago, before the very public uncovering of an alleged plot to blow up aircraft in flight to the USA, the security threat was lower. I don’t actually know what it was but it obviously wasn’t set at ‘critical’. More likely it was ’substantial’ – an attack is a strong possibility – or possibly even ‘moderate’ – an attack is possible, but not likely.

Yet we are being told that the arrests were made and the plot foiled because the attack was imminent. Remember the definition of ‘critical’? An attack is expected imminently. So if the threat was of an imminent attack, then the security level should have been ‘critical’. And now that we are told that all the ‘main players’ are in custody and the attack foiled, the threat level should be reduced.

So let me get this straight. When the security services know that a threat is imminent – just a matter of days away we are told – the official threat level is low. When the alleged attack is scuppered and the conspirators arrested, the threat level is high. Can anyone explain the sense of this bizarre system other than to feed the media frenzy and to allow our politicians maximum spin? because I’m buggered if I can see any sense in it.