Syria does not pose an imminent threat to the United States, and therefore should not be attacked by the United States. The president should be prudent in exercising his power to use force, due to the American public's distaste of taking sides in murky situations with no clear U.S. ally on either side of the conflict.
The current composition of Syrian rebel forces includes American enemies.
The power vacuum that results from a failure of the current Syrian regime could cause far worse consequences for us.
The resources required to assure stability in Syria is tremendous thus requires a huge American commitment. Otherwise another haven and training grounds for terrorists results.
Our interference would leave us with the moral obligation to protect Syrians from terrorist rebel elements.