The UN Syrian peace envoy Lakhdar Brahimi says no country can take the law into its own hands and there must be Security Council approval before any military action is undertaken.
The G20 summit in St Petersburg exposed stark divisions between host Vladimir Putin and US President Obama over Syria.
War emptied the suburb of Yarmouk in southern Damascus of its people. Assad's army holds it, but their prize is a ghost town.
Even in the President's heartland of Baltimore, 95% of voters are against his policy on military intervention in Syria.