The President's horror was plain. 'That's appalling.'

'I use it in my lectures at Sandhurst as an example of a classic guerrilla ambush brilliantly executed,' Miller told him.

Ferguson said, 'It was probably the worst incident in terms of casualties in the whole of the Troubles. Eighteen men dead and more than twenty wounded.'

'So where are you going with this?' the President asked.

Miller took a map from his briefcase and unfolded it. 'Afghanistan, Helmand province. See the road running up to the mountains in the north, the small village of Mirbat and the deep lake beside it? The village is in ruins, the people have moved on. A convoy loaded with technicians and electronic equipment needed to get through to the dam at the head of the valley to repair the hydroelectric system that the Taliban had damaged. Two six-wheel Mastiff armoured patrol vehicles led the way. Besides the drivers, there were twelve Rangers. When they got to Mirbat they found it deserted, got out to explore, and a massive roadside bomb killed six of them instantly and wounded others.'

The President said, 'What next?'

'The remaining Rangers came under sniper fire from across the lake. A Chinook helicopter with an instant response medical team happened to be close by, Brits as a matter of fact. They reached Mirbat in fifteen minutes and landed. As the medics jumped out, a second roadside bomb was activated and the helicopter fireballed.' Miller shrugged. 'The firing stopped, the Taliban cleared off. In all, there were twenty personnel involved. The entire Chinook team were slaughtered, and ten Rangers. Two Rangers survived, along with the driver.'