As Brown unveils his National Security Strategy, Fraser Nelson talks to those in the front line against Islamic extremism. MI5 has expanded successfully, but faces in al-Qa’eda an enemy that is organic, elusive and constantly mutating: gangs built on deadly bravadoTo defeat an enemy, one must first understand him — and this, for years, has been Britain’s principal problem in the war on terror. The identity and profile of the typical British jihadi was a mystery.

‘Nice shoes,’ said a young Zimbabwean looking wistfully at my $40 Nike tennis shoes that I wore when I encountered him sitting on the floor of a completely barren Bata shoe store in the town of Victoria Falls. It was last November and I was in Zimbabwe having crossed the border from Botswana earlier that day. The once charming town that used to teem with travellers from around the globe was more derelict and much emptier than I remembered it from my visit in the early 1990s.

The huge defeat of the Conservative party in the election of 1997 drove the party back into its rural and suburban redoubts and so cut it off from many things which were happening in Britain. It did not want to think about the rise of political Islam. This opting out was part of a wider demoralisation in conservative culture in recent years. In the time of the Millennium, the death of Diana and all that, many conservative-minded people started to say things like, ‘I don’t recognise my own country.