What is the author's opinion on the use of chemical weapons in Syria and who does he believe is responsible?
Dumb because it is obvious Assad never used chemical weapons.  It is clearly the rebels that have used chemical weapons, and not Assad.  Assad has a vast superiority in weapons, so has no need to resort to cheap weapons like chemical weapons, that are not very effective or easy to aim.  The rebels are the ones who don't have good weapons and have always been improvising alternatives like chemical weapons.  The UN can send in inspectors whenever they want, and they have never found any chemical weapons being used or possessed by Assad.  Why would Assad have turned over all his chemical weapons in 2013 if he intended to still use them?  Why would he bother using them at all, since he has much more lethal weapons?