A decade of appalling civil war has left Syria fragmented and in ruins but one thing crosses every front line: a drug called captagon.The stimulant -- once notorious for its association with Islamic State fighters -- has spawned an illegal $10 billion industry that not only props up the pariah regime of President Bashar al-Assad, but many of his enemies.It has turned Syria into the world's latest narco state, and sunk deep roots in neighbouring Lebanon as its economy has collapsed.