A terrorist attack could happen anywhere in Britain
If the UK was hit by a chemical, biological, radiological or nuclear (CBRN) attack would we be able to cope?
Margaret Gilmore looks at the state of preparedness across the UK.
The threat is there. The head of MI5, Eliza Manningham-Buller has told us so.
"It is only a matter of time before a crude version of a CBRN is launched at a major Western city," she said in June last year.
It was a chilling warning - a signal that we are moving into uncharted territory - we simply don't know what impact a chemical, biological, radiological or nuclear attack would have in Britain.
But we need to prepare for this possibility all the same.
A different threat
The attacks in Madrid proved the terrorists have European cities in mind as potential targets. They're already using conventional bombs worldwide and intelligence chiefs believe al-Qaeda has a real interest in developing something more sinister.
SITUATION AROUND THE UK
Click on your nation or region for an overview of the state of preparedness in your area
This means the threat today is very different from anything that's gone before.
A terrorist attack could be massive in scale. It could lead to mass casualties. It could lead to the evacuation of huge numbers of people.
Or it could be small, but have huge psychological impact. Remember the anthrax scares in America after 11 September? Imagine the fear if a handful of people were killed in a chemical attack on the London Underground.
The government is putting most effort into prevention.
It is doubling the size of MI5 and building up counter-terrorist operations here and abroad. But preparing for the worst is also critical.
Here in the UK emergency planners spend all their time preparing for disasters - crises like floods, chemical spillages or foot and mouth disease.
Every county council has an emergency planning department which must by law have emergency plans drawn up. They do this with the help of the emergency services - police, fire, ambulance - and the army.
But 11 September gave them a massive shock. There can't have been a planner in the country who believed they were adequately prepared to cope with the aftermath of a terrorist attack on a scale like that.
It was a wake-up call and it's been catch-up time ever since.
In the three years since, we have seen a huge shift in emphasis, with nearly all new cash and equipment aimed at preparing for a large-scale terrorist or CBRN attack.
That's not always easy for local planners. Those in rural areas are far more likely to experience a natural disaster like a flood, than a bomb.
The most visible change in disaster planning is the rollout of the mobile mass decontamination units
In the first year after 11 September, some emergency planners believe the government talked big but actually did very little.
They complained of a lack of funding and a lack of guidance from central government.
The UK has come a long way since. One Whitehall source in the thick of the fight against terrorism says: "There's always room for improvement. I'd rather be here than in Germany or France, we're better at these things."
Nevertheless there's still a lot more to do.
"We do not pretend to have complete answers," the government's security and intelligence co-coordinator, Sir David Omand said in July, all too aware he has to get things right.
"In the end," he admits, "..the public will judge us by...our ability to deal with the consequences of an attack".
But he has a problem. Much of the planning is secret.
Councils are obliged to prepare emergency plans, yet can't publish them all because they're apparently too sensitive. Tom Brake MP, who's chairman of the National Council for Civil Protection is worried:
"It concerns me that it's hard to get information on how well prepared we are. It means we cannot access how much progress has been made".
There are concerns too about regional disparities.
London for example has an evacuation plan.
But surrounding counties are not convinced they would be able to receive, let alone house and sleep, large numbers of evacuees.
It's likely most police who end up at the scene of a catastrophic attack will not have been trained.
Could the road and rail infrastructure cope with mass evacuation? Who, for example would keep the roads open?
You only have to remember how snow last winter led to thousands of motorists being trapped for many hours on the M11.
Mr Brake says it is a weakness, with areas like the Home Counties, "outside the loop when discussions on preparedness are had".
Manchester, like London is one of the better prepared areas. It boosted its resilience plans ahead of the Commonwealth Games.
Cumbria has good arrangements for dealing with the release of radioactive material because of the nuclear installations at Sellafield.
But many areas worry that since hospitals often run at 85% or more capacity, they would not, in a crisis, be able to deal with a mass influx of patients.
The most visible change in disaster planning is the rollout of the mobile mass decontamination units.
Police, ambulance and firefighters are being trained in how to decontaminate large numbers of people in the event of a chemical or radiological attack, but some say the process is far too slow.
Volunteers are "decontaminated" in a mock attack in the West Midlands
The Police Federation of England and Wales is just one organisation that's concerned.
Five thousand police officers have been trained in what to do in the event of a CBRN attack, a fraction of officers.
It is likely most police who end up at the scene of a catastrophic attack will not have been trained.
The Council for Civil Protection is also worried there are not enough "dry runs". There have been major drills, mainly in London. But the National Council for Civil Protection says the lessons of previous national emergencies have not been learned.
Mr Brake points out: "We should have learned much that would help us in the event of an attack from incidents like the fuel protest. But up to two months ago there had been no dry run for dealing with such an incident."
Yet times are changing. Ian Hoult, emergency planning officer for Hampshire County Council, and a former general secretary of the Emergency Planning Society, is one of many who used to complain about the lack of help and cash from central government. Now he says:
"Since I spoke out two years ago about the inadequacy of the plans made for an emergency, there has been a sharp improvement.
"We now have a civil contingencies bill underway which deals with many problems. In addition there is a new regional structure for dealing with emergencies in a co-ordinated way.
"On top of that there has been a 113% increase in funding for dealing with civil emergencies".
In truth the UK has never been better equipped to deal with a terrorist attack. But nothing can really prepare us for what might happen.
And though the response of the emergency services will be crucial after any attack, the way ordinarily people behave will also be critical.