Lyse Doucet presents the first of a two-part documentary telling the story of the civil war in Syria, revealing how a peaceful uprising about high unemployment, corruption and a lack of political freedom under President Bashar seven years ago has left half a million people dead, devastated numerous cities and drawn in other countries. In the first episode, Doucet tracks the early months of the uprising through to the chemical attack in Ghouta that finally revealed the reluctance of the US to intervene in the war, despite the crossing of President Obama's 'red line' on chemical weapons. Concludes tomorrow.