Westminster terror attack: Lone wolves keep security services up at night

A carving knife. A car. An ideology twisted into madness itself and vanity. These are the ingredients that make for the perfect terrorist.

Membership of a cell of like-minded monsters may have been a source of confidence and a source of inspiration.

But it's the lone wolves who keep the security services up at night.

The Westminster attack on ordinary civilians and police guarding the Houses of Parliament could have been predicted and it was.

:: Witness: 'I saw 8-10 people on the ground'

But short of ending democracy, of closing access to the democratic process and its trappings, short of delivering strategic effect to lunatics and death cult members, by shutting off the mother of parliaments off from the world, very little more could be done to protect the precinct.

Not, that is, unless the United Kingdom turned itself into something resembling the so-called Islamic State or at the very least a nation so preoccupied with its own security that it has lost touch with what it was that was worth protecting.

This is both the physical vulnerability and the philosophical strength that extremists so wish to attack.

The latest London atrocity is an attempt to repeat the Nice mass murder-by-truck committed last year in which 86 people were killed watching Bastille Day celebrations in Nice.

:: First picture of terror attack suspect

It has fallen on the anniversary of last year's Brussels attacks too.

The Nice attack was echoed in the December Christmas market attacks in Berlin. None of them were planned by a terrorist cell following orders from Raqqa, the capital of the so-called Islamic State.

That would have meant that they were vulnerable to penetration and exposure.

:: Live updates on attack

IS and other groups have long understood that all that is required is to find, or make, a fanatic and give them a few basic hints over the internet and the world's attention will be focused on the bloody outcome.

We've seen it in London before with the murder of Lee Rigby in Woolwich. Two semi-deranged wannabe jihadists with egos in inverse proportions to their understanding of Islam can cause mayhem.

But it is worth remembering that these attacks are dramatic but they are tactical assaults. They do not result in strategic change.

Power will still come on, the wheels of commerce and industry will turn and the United Kingdom will not shudder under the impact of a fanatic with a car.

:: Witness: 'A guy ran past me and stabbed cop with big knife'