The big challenge for emergency services teams was trying to ensure victims were reached without compromising their own safety and in the end the task was too difficult. In the aftermath, West Midlands chief inspector Surjeet Manku, said there was a need to assess: “Why decontamination took so long, whether decisions were rationally made and whether there were any communication difficulties.”

Meanwhile detective chief constable Chris Sims, who oversaw Horizon said: “We have got to minimise the time it takes to get this full canopy of resources deployed, and I am sure we will be talking about that…There is a real balance to be struck. It is not just protecting ourselves, it’s about serving casualties.”

In order to simulate reality, emergency services crews had no idea exactly when the attack would come and that made marshalling forces more difficult. It was a full 15 minutes before police threw a protective cordon around the NEC.

“Victims” were also instructed to increase the reality levels of the incident by becoming angry at delays in treatment and trying to break through police Cordons. As the hours went by their “anger” became more genuine and a number had to be “arrested”.

The failure underscores the findings of last year’s mock attack on a London subway station – separate terrorism emergency response units are needed that are always standing by. Both the Bank Underground Station operation and Operation Horizon clearly show that such a joint team needs to be multi-tasking – it must be able to provide policing, fire control and medical assistance all at the same time, circumventing the need for different emergency services departments to try and co-ordinate their operations.

The difficulties of Operation Horizon mirror those experienced by the organisers of Topoff2 held in May, when 8000 emergency workers in the U.S. tried to respond to the biggest “terror attack” so far. The operation involved a simultaneous dirty bomb attack in Seattle and a bioterror stike in Chicago. The subsequent FEMA report was unflattering to say the least.

“Throughout the first two days of the exercise, disagreement (and confusion) resulted between local, state and federal agencies over whether DHS had implemented ‘Orange’ or ‘Red,’ and whether the level was applicable nationally or locally,” the report said.

“What makes the criticism of the exercise particularly worrying for emergency-response experts is that it was one of the most heavily scripted drills ever staged.”

And James Lee Witt, the former head of FEMA, expressed his concern after Topoff2. “It’s my experience that any time you add more layers of bureaucrats into emergency plans, it’s a hindrance,” he said.

It’s likely Australia is even less prepared to handle a serious terrorist attack than its Coalition allies. A recent gas leak at Sydney’s busy Wynyard Station during rush hour brought the city to a complete standstill. Happily it took just 20 minutes to evacuate the entire City Circle rail line but stations were closed for 5 hours and most the city’s metropolitan transport services were thrown into complete chaos.