The Obama administration has closed the US embassy in Damascus and pulled all American diplomats out of Syria. Officials say Ambassador Robert Ford and other diplomats left Syria Monday. It is the most dramatic US move so far after 11 months of a violent crackdown on dissent by President Bashar Al-Assad's regime. The State Department warned last month it would close the embassy unless Assad's government stepped up its protection. It cited concerns about the safety of personnel and recent car bombs. The White House warned Syria's allies that backing Assad was a “losing bet” after China and Russia blocked a UN Security Council resolution. “Betting everything on Assad is a recipe for failure,” White House spokesman Jay Carney said, arguing that the Syrian president's hold on power was “very limited at best.”