New information about the rocket assumed to have delivered poison sarin gas to a Damascus suburb on 21 August last year poses a challenge to U.S. intelligence assertions about that attack, and suggest that the argument U.S. officials initially made for retaliatory military action against the Assad regime was flawed. Security and arms experts, meeting last week in Washington, D.C. to discuss the issue, have concluded that the range of the rocket which delivered sarin in the largest attack that night was too short for the device to have been fired from the Syrian government positions where the Obama administration insists they originated.