‘Al-Qa’eda brain surgeons fail to blow up large car full of petrol’ has an agreeable ring to it, as a sort of taunt at our enemies and as a comfort blanket while we’re standing in the mile-long queue at Heathrow with a sniffer-dog’s snout in our groins. . . Imagine: you join al-Qa’eda, take your medical exams, get a job in a British provincial hospital and spend years patiently plotting, awaiting the right moment and painstakingly growing your beard. An enormous investment of time, money and effort. And then you fill the car full of gasoline and propane and succeed only in setting yourself alight and incurring a few parking fines. Suicide bombers are, by definition, an evolutionary anomaly, a strictly counter-Darwinian development. Maybe the good gene pool has already been blown to smithereens and only the thickoes remain.