BBC in Damascus: How Syria crisis spread
29 August 2013 Last updated at 10:36 BST
As international action on Syria becomes more likely, countries in the region are watching with concern - and taking different sides.
Turkey says the suspected chemical attacks must "not go unpunished", but Iran's Supreme Leader says US action would be "a disaster for the region".
Meanwhile Lebanon continues to bear the brunt of the fallout, with sectarian support for both the Assad regime and the rebels dragging the country into the conflict.
Jeremy Bowen's report starts in Tripoli in Lebanon, before moving to Damascus.