Dame Eliza Manningham-Buller of MI5 has made the unusual step of going public to say that MI5 knows of 30 terror plots threatening the UK and is keeping 1,600 individuals under surveillance.
Do we believe her?
The threat from this quarter is certainly higher than it was before the asinine invasions of Iraq and Afghanistan.
But 30 plots? Here are some reasons why we should treat her remarks with some scepticism.
1. She made it at the same time as asking for more government funds, and government departments always want more funds. And yet MI5 is already twice as big as it was pre-9-11. But do we want to live in a paranoid state? Does the potential threat to a few individuals really justify this level of stress for the whole population?
2. Eliza talks of future threats such as dirty bombs, biological weapons and other horrors, designed to make us rush into her protective arms for safety. I'm sorry, I've heard it before, and even if it may be true, again, the potential threat doesn't make me want to live in the kind of country Eliza wants to create.
3. The timing of her remark comes just a few days after Dhiren Barot was sentenced to at least 40 years in jail for planning a series of attacks, for maximum effect. Fear distorts judgement, and she knows that.
4. An example: over 1,000 arrests have been made under anti-terrorism since 9/11. Out of those, 27 have been found guilty of which only nine have been Muslims. Less than 1% of those arrested.
5. Fear breeds fear. We are in danger of helping to create - as we already have done by our meddling - itself caused by faulty intelligence - more of the very thing we fear.
Let's try and learn from history, get some perspective.
The origin of MI5
Modern Britain began in the 16th century with the foundation of a Protestant state. At that time the majority of the British population was Catholic. Lord Burghley and Francis Walsingham helped to found the secret service - today's MI5 - to protect this fledgling state from real and perceived Catholic plots and bolster the hegemony which they benefited from.
Yes, the motivation was religion and power.
At this time, wonderful innovations were introduced - such as torture on the rack to extort confessions, usually suspect, sanctioned for use by Queen ELizabeth and employed by one of the most perverted sadists ever to serve the British State, a man called Topcliffe.
Walsingham created a network of paid informers, dubious spies, encryption experts, forgers, shady double dealers, fanatics, criminals, businessmen wanting diplomatic help with deals in exchange for information, and agents provocateur, to gather information (or misinformation) about Catholic priests and their supporters at home and abroad, in order to persecute and prosecute them.
Many of these 'plots' were invented, manufactured or helped along for political ends. This eventually resulted in his entrapment of Queen Mary Stuart, and her execution.
There is no difference between the methods used then and now. They just seem to be more sophisticated. Then, as now, Burghley and Walsingham exaggerated the threats for their own purposes. They used all the techniques of modern spin for propaganda. They spread rumours to stir the population against Catholics.
Walsingham even proposed an alliance with Islamic Turkey against Catholic Spain before the Armada.
How things change - or not.
The enemy changed
Only twenty years ago the enemy was still Catholic - the IRA. How distant this seems now.
But there was another enemy in the '80s - so-called anarchists. I myself was allegedly one of these, and operated on the fringes of various activities in London. I saw first hand the absurd attempts of MI5 to infiltrate and spread scare stories about anarchist activities.
At one point an attempt was made to plant an agent in our collective. He was spotted straight away, so inept was he. Simultaneously it emerged that Greenpeace London's group - the one campaigning against McDonald's - contained more agents reporting on each other than it did real members.
Every so often a scare story about an anarchist plot to blow something up would appear in the press, which we knew was a silly season tactic, more to do with MI5's funding needs than reality.
How times have changed - or not.
Of course there is a threat - but mostly it's from misguided little-more-than-children. A simple change of foreign policy will nip most of it in the bud, don't we know.
So should we trust Dame Eliza Manningham-Buller?
I wouldn't trust MI5 further than I'd trust Tony Blair. Can I make it any clearer? I trust my cat more.