Earlier quoted context omitted.
Why not?
* There is overwhelming evidence that the Syrian military has stockpiles of nerve agents and ballistic delivery systems for them. BTW: thanks, Russia. * The FSA on the other hand is conducting raids to get rifle ammunition. * There's the obvious issue that the (apparent) sarin attack targeted a neighborhood that was effectively allied with the FSA and that just happened to be a current critical objective for the Syri…
* Syrian military was driving back the rebels in this particular neighborhood just fine without the use of chemical weapons. So Assad in light of this decides to use significant amounts of nerve gas on the very day that he invited UN inspectors to come back?
* Who said that the sarin used was stolen by the FSA from government stockpiles? In an earlier bust of a rebel holdout there were nerve gas delivery mechanisms discovered which appeared to have been produced in Saudi Arabia.
* Finally there is the case of German warships who were patrolling the area and intercepting Syrian military communications and recordings of Assad repeatedly forbidding use of chemical weapons.