IN a small flat in Damascus, a young man in jeans and T-shirt draws frequently on a Gauloises cigarette as he describes how he dressed his brother in a suicide belt and watched him blow up some American soldiers at a drinks stall in Iraq. The young man calls himself Ahmed. He is 23 and he has a degree in chemistry. He knows all about explosives. Last year, he says coolly, he took 15kg of TNT, packed it into pouches with some nails and strapped the bomb to his 19-year-old brother’s waist. There was never any doubt that it would...