Why won't the President share with us his proof it was Assad?

[another_liberal]

77. I'm not so sure about that.

The rebel forces have rocket launchers, they staged a short-range rocket attack on Assad's own neighborhood in Damascus just a week or two before the gas attack. They boasted they have nerve gas munitions seized from Assad's stockpiles at bases they captured. They also had in their ranks defectors who were trained in the use of chemical weapons while still in the Syrian army. Add to that the fact they have even expressed a willingness to use their chemical weapons, citing, of course, the claim that Assad has used them first as their justification.

In other words: The Rebels had the chemical weapons; they had the delivery systems; they had the experienced personnel and they had the openly stated intention. What more in the way of "capabilities" is required?