"This report offers an operationally informed overview of options for U.S. and allied military intervention in the Syrian civil war using airpower. It does not argue that the United States should intervene in Syria, but seeks to inform discussion of the requirements and risks of various options should such a decision be made." "Key findings: Destroying the Syrian air force or grounding it through intimidation is operationally feasible but would have only marginal benefits for protecting Syrian civilians. ; Neutralizing the Syrian air defense system would be challenging but manageable; however, it would not be an end in itself. ; Defending safe areas in Syria's interior would amount to intervention on the side of the opposition. ; An air campaign against the Syrian army could do more to ensure that the regime fell than to determine its replacement. ; Airpower could reduce the Assad regime's ability or desire to launch chemical weapon attacks, but eliminating its arsenal would require a large ground operation."