Let Syria civil war take its course
Those who served in the military know that once given a mission, response and action should be immediate in order to take advantage of the element of surprise. To do otherwise allows the enemy to prepare, defend or aggress usually ending in a failed mission -- with unnecessary casualties.
The element of a surprise attack on Syria's arsenal of chemical weapons is now history. They have been moved, buried or in locations no longer known to American intelligence and it would be quite a while to establish that once again, if ever.
Assad's abysmal deed has already been done so any 'pin prick' limited strike would be made for what purpose -- a belated reprimand?
The world has been informed of his terrible deed and that he has violated International Law. Should Assad attack his people again, then the world will condemn and act and the United States would not have to go it alone. Thus, I do not think Assad will use chemical weapons again knowing the reaction of the rest of the world. But, he could certainly sell them to support his war and, in that region, there would be plenty of takers.
This is a civil war, much aligned to the Vietnam encounter. Let it take its course -- internally and without our interferences to a sovereign nation's fight, as sad a nation as it is. Yes, innocents will die for no reason and collateral damage will be heavy, but supporting the rebels could very well be detrimental to us since it is rumored they are supported and aided by al-Qaida and other Islamic radicals. This group can very well end up with the chemical weapons and then we would have to be concerned that they will use them against us and very likely on our own soil.