Whenever Afghanistan comes up in conversation, there are nearly always at least one of two myths put forward: firstly, that the only thing being achieved in this war is an increasing death toll of our troops; secondly, that the Afghans do not want us there and they were better off before we invaded.

The brutal images coming from Woolwich could not have been more surreal. A man with bloodied hands holds a knife and explains he has just hacked a British soldier to death on the streets of London in broad daylight.