A series of revelations about the rocket believed to have delivered poison sarin gas to a Damascus suburb last summer are challenging American intelligence assumptions about that attack and suggest that the case U.S. officials initially made for retaliatory military action was flawed. A team of security and arms experts, meeting this week in Washington to discuss the matter, has concluded that the range of the rocket that 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. The authors of a report released Wednesday said that their study of the rocket's design, its likely payload and its possible trajectories show that it would have been impossible for the rocket to have been fired from inside areas controlled by the government of Syrian President Bashar Assad. In the report, titled "Possible Implications of Faulty U.S. Technical Intelligence," Richard Lloyd, a former United Nations weapons inspector, and Theodore Postol, a professor of science, technology and national security policy at the Massachusetts Institute of Technology, argue that the question about the rocket's range indicates a major weakness in the case for military action initially pressed by Obama administration officials. Postol said that a basic analysis of the weapon ... would have shown that it wasn't capable of flying the 6 miles from the center of the Syrian government-controlled part of Damascus to the point of impact in the suburbs, or even the 3.6 miles from the edges of government-controlled ground.