Lebanon Abu Hassan puts down his Kalashnikov and reaches into a pocket on his bodywarmer to hand me a small white pill. ‘Here,’ he says in Arabic, ‘a gift. This’ll keep you awake for 48 hours.’ He grins and adds in English: ‘Good sex!’ The pill is Captagon, an amphetamine known as ‘the poor man’s coke’. It can make the user feel invincible and was taken by fighters on all sides in Syria’s civil war; Isis were said to be big fans of ‘Captain Courage’. It has now spread across the Middle East. You might find Captagon fuelling a party in Riyadh or keeping a Baghdad taxi driver awake through a double shift. It is, of course, illegal. And horribly addictive. It is said to be by far Syria’s biggest export, providing more than 90 per cent of the country’s foreign currency.